Engineering › Electrical and Electronic Engineering

Silicon and Solar Cell Technologies

Works Count: 76056

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Description

This cluster of papers focuses on the advancements in silicon solar cell technology, particularly in improving efficiency, passivation techniques, and the use of heterojunction and interdigitated back contacts. It also explores the influence of aluminum oxide, surface recombination, and the potential of crystalline silicon for photovoltaic applications.

Keywords

Silicon; Solar Cells; Efficiency; Passivation; Heterojunction; Aluminum Oxide; Interdigitated Back Contacts; Photovoltaics; Surface Recombination; Crystalline

Silicon-on-Insulator Technology: Materials to VLSI

2004-01-01

Jean-Pierre Colinge

Transition metals in silicon

1983-01-01

Eicke R. Weber

Modeling of carrier mobility against carrier concentration in arsenic-, phosphorus-, and boron-doped silicon

1983-07-01

G. Masetti , M. Severi , S. Solmi

New carrier mobility data for both arsenic- and boron-doped silicon are presented in the high doping range. The data definitely show that the electron mobility in As-doped silicon is significantly … New carrier mobility data for both arsenic- and boron-doped silicon are presented in the high doping range. The data definitely show that the electron mobility in As-doped silicon is significantly lower than in P-doped silicon for carrier concentrations higher than 10 19 cm -3 . By integrating these data with those previously published, empirical relationships able to model the carrier mobility against carrier concentration in the whole experimental range examined to date (about eight decades in concentration) for As-, P-, and B-doped silicon are derived. Different parameters in the expression for the n-type dopants provide differentiation between the electron mobility in As-and in P-doped silicon. Finally, it is shown that these new expressions, once implemented in the SUPREM II process simulator, lead to reduced errors in the simulation of the sheet resistance values.

A self-consistent iterative scheme for one-dimensional steady state transistor calculations

1964-10-01

H.K. Gummel

A self-consistent iterative scheme for the numerical calculation of dc potentials and currents in a one-dimensional transistor model is presented. Boundary conditions are applied only at points representing contacts. Input … A self-consistent iterative scheme for the numerical calculation of dc potentials and currents in a one-dimensional transistor model is presented. Boundary conditions are applied only at points representing contacts. Input data are: doping profile, parameters governing excess carrier recombination, parameters describing the dependence of mobility on doping and on electric field, applied emitter and collector voltages, and a trial solution for the electrostatic potential. The major limitation of the present approach results from use of Boltzmann rather than Fermi statistics. Convergence of the iteration scheme is good for low and moderate injection levels.

Defects in Irradiated Silicon: Electron Paramagnetic Resonance of the Divacancy

1965-04-19

G. D. Watkins , J. W. Corbett

Two electron paramagnetic resonance spectra produced in silicon by 1.5-MeV electron irradiation are described. Labeled Si-G6 and Si-G7, they are identified as arising from the singly positive and singly negative … Two electron paramagnetic resonance spectra produced in silicon by 1.5-MeV electron irradiation are described. Labeled Si-G6 and Si-G7, they are identified as arising from the singly positive and singly negative charged states of the divacancy, respectively. The observed hyperfine interactions with neighboring ${\mathrm{Si}}^{29}$ nuclei and $g$ tensors are discussed in terms of a simple molecular-orbital treatment of the defect by the method of linear combination of atomic orbitals. In addition to the anisotropy associated with the vacancy-vacancy direction in the lattice, an additional distortion occurs which is identified as a manifestation of the Jahn-Teller effect. Thermally activated reorientation from one Jahn-Teller distortion direction to another causes motional broadening and narrowing effects upon both spectra in the temperature region 40-110\ifmmode^\circ\else\textdegree\fi{}K. The motion is also studied by stress-induced alignment at lower temperatures, and the activation energy for the process is found to be \ensuremath{\sim}0.06 eV for each charge state. Alignment of the vacancy-vacancy axis direction in the lattice is also achieved by stressing at elevated temperatures. The activation energy for this reorientation process is \ensuremath{\sim}1.3 eV. The magnitude and sense of the alignment in both kinds of stress experiments are consistent with the microscopic model of the defect. It is pointed out that when the divacancy reorients its vacancy-vacancy axis, it is also diffusing through the lattice. The 1.3 eV is therefore also its activation energy for diffusion. Analysis of higher temperature annealing studies allow a lower limit estimate for the binding energy of the two vacancies as $\ensuremath{\gtrsim}1.6$ eV. The electrical level structure is deduced and it is concluded that the divacancy introduces one donor and two acceptor levels in the forbidden gap.

Anisotropic etching of silicon

1978-10-01

K.E. Bean

Anisotropic etching of silicon has become an important technology in silicon semiconductor processing during the past ten years. It will continue to gain stature and acceptance as standard processing technology … Anisotropic etching of silicon has become an important technology in silicon semiconductor processing during the past ten years. It will continue to gain stature and acceptance as standard processing technology in the next few years. Anisotropic etching of (100) orientation silicon is being widely used today and (110) orientation technology is emerging. This paper discusses both orientation-dependent and concentration-dependent etching of (100) and (110) silicon. Very exact process control steps may be designed into a process by use of (100) anisotropic and concentration-dependent etching. Also, methods of oxide or nitride pin hole detection in (100) silicon are presented. Mask alignments to obtain different etch front termination in both (100) and (110) silicon are shown. Very high packing density structures, less than 1 μm, are obtained in the (110) technology, and extremely high etching ratios of greater than 650 to 1 are obtained in (110) orientation-dependent etching. Some of the many applications for anisotropic and concentration-dependent etching are described.

Ion Implantation in Semiconductors

1969-01-01

James W. Mayer , O. J. Marsh

Nonlinear Minimization Algorithm for Determining the Solar Cell Parameters with Microcomputers

1986-01-01

T. Easwarakhanthan , J. Bottin , I. BOUHOUCH +1 more

A nonlinear least-squares optimization algorithm based on the Newton model modified with Levenberg parameter, is described for the extraction of the five illuminated solar cell parameters from the experimental data. … A nonlinear least-squares optimization algorithm based on the Newton model modified with Levenberg parameter, is described for the extraction of the five illuminated solar cell parameters from the experimental data. An initialization routine based on the reduced nonlinear least-squares technique in which only two parameters have to be initialized, is introduced to overcome the difficulty in initializing the cell parameters. The program when incorporated into a microcomputer-based data acquisition software, allows an in-situ theoretical modelling of solar cells in laboratories. Results obtained for a commercial solar cell and a module are given.

Hydrogen in Crystalline Semiconductors

1992-01-01

S. J. Pearton , J. W. Corbett , Michael Stavola

Increasing the Efficiency of Ideal Solar Cells by Photon Induced Transitions at Intermediate Levels

1997-06-30

A. Ĺuque , Antonio Martı́

Recent attempts have been made to increase the efficiency of solar cells by introducing an impurity level in the semiconductor band gap. We present an analysis of such a structure … Recent attempts have been made to increase the efficiency of solar cells by introducing an impurity level in the semiconductor band gap. We present an analysis of such a structure under ideal conditions. We prove that its efficiency can exceed not only the Shockley and Queisser efficiency for ideal solar cells but also that for ideal two-terminal tandem cells which use two semiconductors, as well as that predicted for ideal cells with quantum efficiency above one but less than two.

Ultralow surface recombination of c-Si substrates passivated by plasma-assisted atomic layer deposited Al2O3

2006-07-24

Bram Hoex , S. B. S. Heil , E. Langereis +2 more

Excellent surface passivation of c-Si has been achieved by Al2O3 films prepared by plasma-assisted atomic layer deposition, yielding effective surface recombination velocities of 2 and 13cm∕s on low resistivity n- … Excellent surface passivation of c-Si has been achieved by Al2O3 films prepared by plasma-assisted atomic layer deposition, yielding effective surface recombination velocities of 2 and 13cm∕s on low resistivity n- and p-type c-Si, respectively. These results obtained for ∼30nm thick Al2O3 films are comparable to state-of-the-art results when employing thermal oxide as used in record-efficiency c-Si solar cells. A 7nm thin Al2O3 film still yields an effective surface recombination velocity of 5cm∕s on n-type silicon.

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A review of some charge transport properties of silicon

1977-02-01

Carlo Jacoboni , C. Canali , G. Ottaviani +1 more

Advances in crystalline silicon solar cell technology for industrial mass production

2010-07-01

Tatsuo Saga

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Unusually Low Surface-Recombination Velocity on Silicon and Germanium Surfaces

1986-07-14

Eli Yablonovitch , David L. Allara , Che-Chen Chang +2 more

We have found that a standard, widespread, chemical-preparation method for silicon, oxidation followed by an HF etch, results in a surface which from an electronic point of view is remarkably … We have found that a standard, widespread, chemical-preparation method for silicon, oxidation followed by an HF etch, results in a surface which from an electronic point of view is remarkably inactive. With preparation in this manner, the surface-recombination velocity on Si111> is only 0.25 cm/sec, which is the lowest value ever reported for any semiconductor. Multiple-internal-reflection infrared spectroscopy shows that the surface appears to be covered by covalent Si-H bonds, leaving virtually no surface dangling bonds to act as recombinatiuon centers. These results have implications for the ultimate efficiency of silicon solar cells.

Theoretical Considerations Governing the Choice of the Optimum Semiconductor for Photovoltaic Solar Energy Conversion

1956-07-01

J. J. Loferski

The theory of the photovoltaic effect is used to predict the characteristics of a semiconductor which would operate with an optimum efficiency as a photovoltaic solar energy converter. The existence … The theory of the photovoltaic effect is used to predict the characteristics of a semiconductor which would operate with an optimum efficiency as a photovoltaic solar energy converter. The existence of such an optimum material results from the interaction between the optical properties of the semiconductor which determine what fraction of the solar spectrum is utilized and its electrical properties which determine the maximum efficiency of conversion into electricity. Considerable attention is devoted to the effect of the forbidden energy gap (EG) of the semiconductor. It is shown that atmospheric absorption causes a shift in the solar spectrum which changes the value of the optimum forbidden energy gap between the limits 1.2 ev&lt;EG &lt;1.6 ev. Furthermore, plausible departures of the diode reverse saturation current (I0) from the parametric dependence predicted by Shockley are considered, and it is shown that such departures reduce the advantage of the optimum material over others in the range 1.1 ev&lt;EG&lt;2.0 ev. The relation between EG and the load impedance for maximum power transfer from the solar converter is discussed. Finally, I0 is computed from the published values of the semiconductor parameters of three intermetallic compounds, i.e., InP, GaAs, and CdTe, and it is shown that the efficiencies predicted for these materials are greater than those predicted for other materials which have been proposed, i.e., Si, CdS, Se, and AlSb.

24.7% Record Efficiency HIT Solar Cell on Thin Silicon Wafer

2013-10-04

Mikio Taguchi , Ayumu Yano , Satoshi Tohoda +5 more

A new record conversion efficiency of 24.7% was attained at the research level by using a heterojunction with intrinsic thin-layer structure of practical size (101.8 cm 2 , … A new record conversion efficiency of 24.7% was attained at the research level by using a heterojunction with intrinsic thin-layer structure of practical size (101.8 cm 2 , total area) at a 98-μm thickness. This is a world height record for any crystalline silicon-based solar cell of practical size (100 cm 2 and above). Since we announced our former record of 23.7%, we have continued to reduce recombination losses at the hetero interface between a-Si and c-Si along with cutting down resistive losses by improving the silver paste with lower resistivity and optimization of the thicknesses in a-Si layers. Using a new technology that enables the formation of a-Si layer of even higher quality on the c-Si substrate, while limiting damage to the surface of the substrate, the V oc has been improved from 0.745 to 0.750 V. We also succeeded in improving the fill factor from 0.809 to 0.832.

A unified mobility model for device simulation—I. Model equations and concentration dependence

1992-07-01

D.B.M. Klaassen

How I Discovered Phase Contrast

1955-03-11

F. Zernike

22.8% efficient silicon solar cell

1989-09-25

Andrew Blakers , Aihua Wang , A.M. Milne +2 more

A new silicon solar cell structure, the passivated emitter and rear cell, is described. The cell structure has yielded independently confirmed efficiencies of up to 22.8%, the highest ever reported … A new silicon solar cell structure, the passivated emitter and rear cell, is described. The cell structure has yielded independently confirmed efficiencies of up to 22.8%, the highest ever reported for a silicon cell.

Vibrational Properties of Imperfect Crystals with Large Defect Concentrations

1967-04-15

David Taylor

The multiple-scattering theory of Lax is used to give equations for the displacement-displacement Green's functions for a crystal containing substitutional defect atoms. A self-consistent method is described within this formalism … The multiple-scattering theory of Lax is used to give equations for the displacement-displacement Green's functions for a crystal containing substitutional defect atoms. A self-consistent method is described within this formalism that is most suitable for large concentrations of mass defects. The essential approximation is best in three dimensions, but even then is not completely satisfactory for low concentrations of light defects. The resulting self-consistent equation is solved numerically using realistic three-dimensional densities of states. The behavior of the density of states and spectral functions for the imperfect crystal is discussed in some detail for different concentrations and mass ratios. The results are compared with recent machine calculations and found to be in good agreement. They are also used to reinterpret experimental results for Ge-Si alloys with some success.

Carrier mobilities in silicon empirically related to doping and field

1967-01-01

D.M. Caughey , R.E. Thomas

Equations are presented which fit the experimental dependence of carrier mobilities on doping density and field strength in silicon. The curve-fitting procedures are described. Equations are presented which fit the experimental dependence of carrier mobilities on doping density and field strength in silicon. The curve-fitting procedures are described.

Statistics of the Recombinations of Holes and Electrons

1952-09-01

W. Shockley , W. T. Read

The statistics of the recombination of holes and electrons in semiconductors is analyzed on the basis of a model in which the recombination occurs through the mechanism of trapping. A … The statistics of the recombination of holes and electrons in semiconductors is analyzed on the basis of a model in which the recombination occurs through the mechanism of trapping. A trap is assumed to have an energy level in the energy gap so that its charge may have either of two values differing by one electronic charge. The dependence of lifetime of injected carriers upon initial conductivity and upon injected carrier density is discussed.

Photon-Radiative Recombination of Electrons and Holes in Germanium

1954-06-15

W. van Roosbroeck , W. Shockley

The spectral distribution of the rate of photon generation for the photon-radiative recombination of electrons and holes in germanium is determined from known optical properties by application of the principle … The spectral distribution of the rate of photon generation for the photon-radiative recombination of electrons and holes in germanium is determined from known optical properties by application of the principle of detailed balance. Quantities characterizing the process are evaluated: The thermal equilibrium recombination rate at 300\ifmmode^\circ\else\textdegree\fi{}K is 1.57\ifmmode\times\else\texttimes\fi{}${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ ${\mathrm{sec}}^{\ensuremath{-}1}$, which corresponds to a recombination cross section of 2.9\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}21}$ ${\mathrm{cm}}^{2}$ and a decay time for a small disturbance in carrier concentration in intrinsic material of 0.75 sec. The extension to the steady-state case of added current carriers is given, and estimates are included of the dependence of the quantities on temperature.

The Distribution of Solute in Crystals Grown from the Melt. Part I. Theoretical

1953-11-01

Justin Burton , R. C. Prim , W. P. Slichter

The incorporation of solute elements into single crystals of germanium grown from the melt is examined in terms of a simple model. The theory takes account of the contribution of … The incorporation of solute elements into single crystals of germanium grown from the melt is examined in terms of a simple model. The theory takes account of the contribution of solute transport in the melt, owing to diffusion and fluid motion, to the over-all process of impurity incorporation during steady-state crystallization. The analysis is extended to treat the transient inclusion of solute which results when the composition of the melt is abruptly changed.

Electrical Properties of Silicon Containing Arsenic and Boron

1954-10-01

François Morin , J. P. Maita

Electrical conductivity and Hall effect have been measured from 10\ifmmode^\circ\else\textdegree\fi{} to 1100\ifmmode^\circ\else\textdegree\fi{} Kelvin on single-crystal silicon containing arsenic and boron. Extrinsic carrier concentration is computed from Hall coefficient. Analysis of … Electrical conductivity and Hall effect have been measured from 10\ifmmode^\circ\else\textdegree\fi{} to 1100\ifmmode^\circ\else\textdegree\fi{} Kelvin on single-crystal silicon containing arsenic and boron. Extrinsic carrier concentration is computed from Hall coefficient. Analysis of extrinsic carrier concentration indicates the ionization energy of arsenic donor levels to be 0.049 ev and of boron acceptor levels to be 0.045 ev for low impurity concentrations. Fermi degeneracy is found to occur in the range ${10}^{18}$ to ${10}^{19}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ impurity concentration. Extrinsic Hall mobility is computed from Hall coefficient and conductivity. Curves of Hall mobility against resistivity at 300\ifmmode^\circ\else\textdegree\fi{}K are computed from theory and compared with experiment. The temperature dependence of lattice-scattering mobility is found from conductivity to be ${T}^{\ensuremath{-}2.6}$ for electrons and ${T}^{\ensuremath{-}2.3}$ for holes. From conductivity mobility and intrinsic conductivity, it is found that carrier concentration at any temperature below 700\ifmmode^\circ\else\textdegree\fi{}K is given by the expression: $np=1.5\ifmmode\times\else\texttimes\fi{}{10}^{33}{T}^{3}\mathrm{exp}(\ensuremath{-}\frac{1.21}{\mathrm{kT}})$. The temperature dependence of the ratio Hall mobility/conductivity mobility is determined for holes and electrons.

Self-consistent optical parameters of intrinsic silicon at 300K including temperature coefficients

2008-07-28

Martin A. Green

Improved quantitative description of Auger recombination in crystalline silicon

2012-10-09

Armin Richter , Stefan W. Glunz , Florian Werner +2 more

An accurate quantitative description of the Auger recombination rate in silicon as a function of the dopant density and the carrier injection level is important to understand the physics of … An accurate quantitative description of the Auger recombination rate in silicon as a function of the dopant density and the carrier injection level is important to understand the physics of this fundamental mechanism and to predict the physical limits to the performance of silicon based devices. Technological progress has permitted a near suppression of competing recombination mechanisms, both in the bulk of the silicon crystal and at the surfaces. This, coupled with advanced characterization techniques, has led to an improved determination of the Auger recombination rate, which is lower than previously thought. In this contribution we present a systematic study of the injection-dependent carrier recombination for a broad range of dopant concentrations of high-purity $n$-type and $p$-type silicon wafers passivated with state-of-the-art dielectric layers of aluminum oxide or silicon nitride. Based on these measurements, we develop a general parametrization for intrinsic recombination in crystalline silicon at 300 K consistent with the theory of Coulomb-enhanced Auger and radiative recombination. Based on this improved description we are able to analyze physical aspects of the Auger recombination mechanism such as the Coulomb enhancement.

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Status and prospects of Al2O3-based surface passivation schemes for silicon solar cells

2012-07-01

G. Dingemans , W. M. M. Kessels

The reduction in electronic recombination losses by the passivation of silicon surfaces is a critical enabler for high-efficiency solar cells. In 2006, aluminum oxide (Al2O3) nanolayers synthesized by atomic layer … The reduction in electronic recombination losses by the passivation of silicon surfaces is a critical enabler for high-efficiency solar cells. In 2006, aluminum oxide (Al2O3) nanolayers synthesized by atomic layer deposition (ALD) emerged as a novel solution for the passivation of p- and n-type crystalline Si (c-Si) surfaces. Today, high efficiencies have been realized by the implementation of ultrathin Al2O3 films in laboratory-type and industrial solar cells. This article reviews and summarizes recent work concerning Al2O3 thin films in the context of Si photovoltaics. Topics range from fundamental aspects related to material, interface, and passivation properties to synthesis methods and the implementation of the films in solar cells. Al2O3 uniquely features a combination of field-effect passivation by negative fixed charges, a low interface defect density, an adequate stability during processing, and the ability to use ultrathin films down to a few nanometers in thickness. Although various methods can be used to synthesize Al2O3, this review focuses on ALD—a new technology in the field of c-Si photovoltaics. The authors discuss how the unique features of ALD can be exploited for interface engineering and tailoring the properties of nanolayer surface passivation schemes while also addressing its compatibility with high-throughput manufacturing. The recent progress achieved in the field of surface passivation allows for higher efficiencies of industrial solar cells, which is critical for realizing lower-cost solar electricity in the near future.

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Electron and hole mobilities in silicon as a function of concentration and temperature

1982-02-01

Neha Arora , John R. Hauser , D.J. Roulston

An analytical expression has been derived for the electron and hole mobility in silicon based on both experimental data and modified Brooks-Herring theory of mobility. The resulting expression allows one … An analytical expression has been derived for the electron and hole mobility in silicon based on both experimental data and modified Brooks-Herring theory of mobility. The resulting expression allows one to obtain electron and hole mobility as a function of concentration up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\sim 10^{20}</tex> cm -3 in an extended and continuous temperature range (250-500 K) within ± 13 percent of the reported experimental values.

Point defects and dopant diffusion in silicon

1989-04-01

P. Fahey , Peter B. Griffin , J.D. Plummer

Diffusion in silicon of elements from columns III and V of the Periodic Table is reviewed in theory and experiment. The emphasis is on the interactions of these substitutional dopants … Diffusion in silicon of elements from columns III and V of the Periodic Table is reviewed in theory and experiment. The emphasis is on the interactions of these substitutional dopants with point defects (vacancies and interstitials) as part of their diffusion mechanisms. The goal of this paper is to unify available experimental observations within the framework of a set of physical models that can be utilized in computer simulations to predict diffusion processes in silicon. The authors assess the present state of experimental data for basic parameters such as point-defect diffusivities and equilibrium concentrations and address a number of questions regarding the mechanisms of dopant diffusion. They offer illustrative examples of ways that diffusion may be modeled in one and two dimensions by solving continuity equations for point defects and dopants. Outstanding questions and inadequacies in existing formulations are identified by comparing computer simulations with experimental results. A summary of the progress made in this field in recent years and of directions future research may take is presented.

Reassessment of the Limiting Efficiency for Crystalline Silicon Solar Cells

2013-07-10

Armin Richter , Martin Hermle , Stefan W. Glunz

Recently, several parameters relevant for modeling crystalline silicon solar cells were improved or revised, e.g., the international standard solar spectrum or properties of silicon such as the intrinsic recombination rate … Recently, several parameters relevant for modeling crystalline silicon solar cells were improved or revised, e.g., the international standard solar spectrum or properties of silicon such as the intrinsic recombination rate and the intrinsic carrier concentration. In this study, we analyzed the influence of these improved state-of-the-art parameters on the limiting efficiency for crystalline silicon solar cells under 1-sun illumination at 25°C, by following the narrow-base approximation to model ideal solar cells. We also considered bandgap narrowing, which was not addressed so far with respect to efficiency limitation. The new calculations that are presented in this study result in a maximum theoretical efficiency of 29.43% for a 110-μm-thick solar cell made of undoped silicon. A systematic calculation of the I-V parameters as a function of the doping concentration and the cell thickness together with an analysis of the loss current at maximum power point provides further insight into the intrinsic limitations of silicon solar cells.

Carrier Generation and Recombination in P-N Junctions and P-N Junction Characteristics

1957-09-01

Chih‐Tang Sah , Robert N. Noyce , W. Shockley

For certain p-n junctions, it has been observed that the measured current-voltage characteristics deviate from the ideal case of the diffusion model. It is the purpose of this paper to … For certain p-n junctions, it has been observed that the measured current-voltage characteristics deviate from the ideal case of the diffusion model. It is the purpose of this paper to show that the current due to generation and recombination of carriers from generation-recombination centers in the space charge region of a p-n junction accounts for the observed characteristics. This phenomenon dominates in semiconductors with large energy gap, low lifetimes, and low resistivity. This model not only accounts for the nonsaturable reverse current, but also predicts an apparent exp (qV/nkT) dependence of the forward current in a p-n junction. The relative importance of the diffusion current outside the space charge layer and the recombination current inside the space charge layer also explains the increase of the emitter efficiency of silicon transistors with emitter current. A correlation of the theory with experiment indicates that the energy level of the centers is a few kT from the intrinsic Fermi level.

Optical properties and electronic structure of amorphous Ge and Si

1968-01-01

J. Tauc

Defects in Irradiated Silicon. I. Electron Spin Resonance of the Si-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>A</mml:mi></mml:math>Center

1961-02-15

G. D. Watkins , J. W. Corbett

The Si-$A$ center is a major, radiation-damage defect produced in "pulled" silicon by a room temperature irradiation. As a result of studies described in this paper (I), and the following … The Si-$A$ center is a major, radiation-damage defect produced in "pulled" silicon by a room temperature irradiation. As a result of studies described in this paper (I), and the following one (II), it is concluded that this center is a lattice vacancy with an oxygen atom impurity bridging two of the four broken bonds associated with the vacancy. Spin resonance and electrical activity arise from an electron trapped in the other two bonds. In this paper (I), the spin resonance studies are described. A molecular orbital treatment of the trapped electron wave-function satisfactorily accounts for the observed $g$ tensor, as well as the hyperfine interaction observed with neighboring 4.7% abundant ${\mathrm{Si}}^{29}$ nuclei. Study of the changes in the spectrum of a sample subjected to uniaxial stress are also described. Under stress, the amplitudes of the individual resonance components (which correspond to different orientations of the defect in the crystal) are observed to change. This results from (1) electronic redistribution of the trapped electrons among the defects, and (2) thermally activated reorientation of the defects themselves under the applied stress. These two effects are separated and a quantitative study of their magnitudes and signs, as well as their rates, is given. The results confirm many of the important microscopic features of the model.

Achievement of More Than 25% Conversion Efficiency With Crystalline Silicon Heterojunction Solar Cell

2014-09-10

K. Masuko , Masato Shigematsu , Taiki Hashiguchi +7 more

The crystalline silicon heterojunction structure adopted in photovoltaic modules commercialized as Panasonic's HIT has significantly reduced recombination loss, resulting in greater conversion efficiency. The structure of an interdigitated back contact … The crystalline silicon heterojunction structure adopted in photovoltaic modules commercialized as Panasonic's HIT has significantly reduced recombination loss, resulting in greater conversion efficiency. The structure of an interdigitated back contact was adopted with our crystalline silicon heterojunction solar cells to reduce optical loss from a front grid electrode, a transparent conducting oxide (TCO) layer, and a-Si:H layers as an approach for exceeding the conversion efficiency of 25%. As a result of the improved short-circuit current (J sc ), we achieved the world's highest efficiency of 25.6% for crystalline silicon-based solar cells under 1-sun illumination (designated area: 143.7 cm 2 ).

Solid Solubilities of Impurity Elements in Germanium and Silicon*

1960-01-01

F. A. Trumbore

The available data on solid solubilities of impurity elements in germanium and silicon are summarized in the form of solidus or solvus curves. New solubility data are presented for the … The available data on solid solubilities of impurity elements in germanium and silicon are summarized in the form of solidus or solvus curves. New solubility data are presented for the lead-germanium, zinc-germanium, indium-germanium, antimony-silicon, gallium-silicon and aluminum-silicon systems. The correlation of the solid solubilities with the heats of sublimation and the atom sizes of the impurity elements is considered.

The Si-SiO2Interface - Electrical Properties as Determined by the Metal-Insulator-Silicon Conductance Technique

1967-07-08

E. H. Nicollian , A. Goetzberger

Measurements of the equivalent parallel conductance of metal-insulator-semiconductor (MIS) capacitors are shown to give more detailed and accurate information about interface states than capacitance measurements. Experimental techniques and methods of … Measurements of the equivalent parallel conductance of metal-insulator-semiconductor (MIS) capacitors are shown to give more detailed and accurate information about interface states than capacitance measurements. Experimental techniques and methods of analysis are described. From the results of the conductance technique, a realistic characterization of the Si–SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> interface is developed. Salient features are: A continuum of states is found across the band gap of the silicon. Capture cross sections for holes and electrons are independent of energy over large portions of the band gap. The surface potential is subject to statistical fluctuations arising from various sources. The dominant contribution in the samples measured arises from a random distribution of surface charge. The fluctuating surface potential causes a dispersion of interface state time constants in the depletion region. In the weak inversion region the dispersion is eliminated by interaction between interface states and the minority carrier band. A single time constant results. From the experimentally established facts, equivalent circuits accurately describing the measurements are constructed.

Measurement of the ionization rates in diffused silicon p-n junctions

1970-05-01

R. Van Overstraeten , Harry de Man

Review of displacement damage effects in silicon devices

2003-06-01

J. R. Srour , Cheryl J. Marshall , Paul W. Marshall

This paper provides a historical review of the literature on the effects of radiation-induced displacement damage in semiconductor materials and devices. Emphasis is placed on effects in technologically important bulk … This paper provides a historical review of the literature on the effects of radiation-induced displacement damage in semiconductor materials and devices. Emphasis is placed on effects in technologically important bulk silicon and silicon devices. The primary goals are to provide a guide to displacement damage literature, to offer critical comments regarding that literature in an attempt to identify key findings, to describe how the understanding of displacement damage mechanisms and effects has evolved, and to note current trends. Selected tutorial elements are included as an aid to presenting the review information more clearly and to provide a frame of reference for the terminology used. The primary approach employed is to present information qualitatively while leaving quantitative details to the cited references. A bibliography of key displacement-damage information sources is also provided.

The path to 25% silicon solar cell efficiency: History of silicon cell evolution

2009-03-25

Martin A. Green

Abstract The first silicon solar cell was reported in 1941 and had less than 1% energy conversion efficiency compared to the 25% efficiency milestone reported in this paper. Standardisation of … Abstract The first silicon solar cell was reported in 1941 and had less than 1% energy conversion efficiency compared to the 25% efficiency milestone reported in this paper. Standardisation of past measurements shows there has been a 57% improvement between confirmed results in 1983 and the present result. The features of the cell structure responsible for the most recent performance increase are described and the history of crystalline and multicrystalline silicon cell efficiency evolution is documented. Copyright © 2009 John Wiley & Sons, Ltd.

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High-efficiency crystalline silicon solar cells: status and perspectives

2016-01-01

Corsin Battaglia , Andrés Cuevas , Stefaan De Wolf

With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from … With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses key factors responsible for the success of the classic dopant-diffused silicon homojunction solar cell. Next it analyzes two archetypal high-efficiency device architectures – the interdigitated back-contact silicon cell and the silicon heterojunction cell – both of which have demonstrated power conversion efficiencies greater than 25%. Last, it gives an up-to-date summary of promising recent pathways for further efficiency improvements and cost reduction employing novel carrier-selective passivating contact schemes, as well as tandem multi-junction architectures, in particular those that combine silicon absorbers with organic–inorganic perovskite materials.

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High-efficiency Silicon Heterojunction Solar Cells: A Review

2012-03-08

Stefaan De Wolf , Antoine Descoeudres , Zachary C. Holman +1 more

Abstract Silicon heterojunction solar cells consist of thin amorphous silicon layers deposited on crystalline silicon wafers. This design enables energy conversion efficiencies above 20% at the industrial production level. The … Abstract Silicon heterojunction solar cells consist of thin amorphous silicon layers deposited on crystalline silicon wafers. This design enables energy conversion efficiencies above 20% at the industrial production level. The key feature of this technology is that the metal contacts, which are highly recombination active in traditional, diffused-junction cells, are electronically separated from the absorber by insertion of a wider bandgap layer. This enables the record open-circuit voltages typically associated with heterojunction devices without the need for expensive patterning techniques. This article reviews the salient points of this technology. First, we briefly elucidate device characteristics. This is followed by a discussion of each processing step, device operation, and device stability and industrial upscaling, including the fabrication of solar cells with energy-conversion efficiencies over 21%. Finally, future trends are pointed out.

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Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26%

2017-03-20

Kunta Yoshikawa , Hayato Kawasaki , Wataru Yoshida +7 more

Hydrogen in crystalline semiconductors

1987-07-01

S. J. Pearton , J. W. Corbett , Tiansheng Shi

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Semiconductor Silicon

1989-01-01

Changing the Absorber Layer with a Compound FeSi2 to Improve the Efficiency of the Solar Cell using a Simulation Program

2025-06-24

| Deleted Journal

Impact of Er‐Based Atomic Layer Deposited Upconverting Oxides on Si Solar Cell Surface Passivation

2025-06-24

Behrad Radfar , Amr Ghazy , Joona Pekkanen +4 more | physica status solidi (a)

Crystalline silicon solar cells face fundamental limitations in infrared (IR) absorption leading to significant solar energy losses. Using upconverting (UC) rare‐earth oxide layers is a potential solution to convert sub‐bandgap … Crystalline silicon solar cells face fundamental limitations in infrared (IR) absorption leading to significant solar energy losses. Using upconverting (UC) rare‐earth oxide layers is a potential solution to convert sub‐bandgap photons into higher‐energy photons that Si can absorb. However, integrating UC layers into solar cells can potentially affect surface passivation properties, which may result in recombination of photogenerated charge carriers at Si/UC interface. This study investigates the impact of atomic‐layer‐deposited mixed rare‐earth oxide (Y,Er,Ho) 2 O 3 and Er 2 O 3 UC layers on the passivation quality of Si interface, deposited directly on Si substrate or on the conventional passivation layers, i.e., SiO 2 and Al 2 O 3 . Findings reveal that direct deposition provides very weak passivation (τ eff ≈ 4.1 μs) which does not improve with post‐deposition annealing. Similarly, when deposited on top of SiO 2 with optically relevant thickness, the resulting passivation is poor. However, UC layer on top of Al 2 O 3 does not compromise the passivation performance, resulting in low surface recombination velocity of 1.5 cm s −1 for Er 2 O 3 and 1.4 cm s −1 for (Y,Er,Ho) 2 O 3 . Consequently, the results indicate that it should be viable to integrate UC layer like Er 2 O 3 into a state‐of‐the‐art solar cell to improve sub‐bandgap absorption without compromising the passivation properties.

Optimizing Semiconductor-insulator-semiconductor Heterojunction Engineering Performance in a Novel High-efficiency Solar Cell Structure

2025-06-24

Ahmed Bouriche , C. E. Benouis , M. Benhaliliba +1 more | Periodica Polytechnica Chemical Engineering

In this study, we introduce and optimize a novel semiconductor-insulator-semiconductor (SIS) solar cell using SCAPS-1D simulations. The Pt/Si/TiO2/ZnSe/ fluorine-doped tin oxide (FTO), structure employs Pt and FTO as back/front contacts. … In this study, we introduce and optimize a novel semiconductor-insulator-semiconductor (SIS) solar cell using SCAPS-1D simulations. The Pt/Si/TiO2/ZnSe/ fluorine-doped tin oxide (FTO), structure employs Pt and FTO as back/front contacts. TiO2 serves as a critical insulating layer between p-Si and n-ZnSe, enhancing electrical isolation while boosting stability and efficiency through reduced recombination and improved charge transport. Results demonstrate TiO2 as an insulating material significantly improves the fill factor (FF) and power conversion efficiency (PCE) of the device, compared to conventional structures. Key optimized parameters include: Si 1300 nm, ZnSe 100 nm, and TiO2 insulating layer to 10 nm; defect densities of 1015 cm−3 for both Si and ZnSe, and 1012 cm−3 for the interfaces. This optimized cell demonstrates the following performance results: a VOC of 0.84 V, a JSC of 42.09 mA cm−2, an FF of 86.42%, and a PCE of 30.65%. These results were achieved under standard test conditions (AM1.5G, temperature of 300 K). Our simulations focus on enhancing electrical parameters, particularly efficiency. This study will provide valuable parameters for any future experimental work on SIS solar cells.

Defect Density Analysis of WOx and MoOx Thin Films Grown by Pulsed Laser Deposition for Heterojunction Solar Cell Applications

2025-06-23

Daniele Scirè , Roberto Macaluso , Mauro Mosca +4 more | ACS Applied Energy Materials

Reduction of silver content in Electrically Conductive Adhesives for low-temperature interconnection of solar cells

2025-06-23

Nathalie Ronayette , Olivier Poncelet , Sónia S. Nobre +3 more | Solar Energy Materials and Solar Cells

Effect of Firing Temperature on Damp Heat Stability of n‐TOPCon Solar Cells’ Rear Side

2025-06-23

Zhiwei Li , Jiali Tang , Kai Yu +7 more | Solar RRL

Laser‐enhanced contact optimization (LECO) technology is one of the ideal candidates to reduce front contact resistance and metal‐induced recombination of n‐type tunnel oxide‐passivated contact (n‐TOPCon) solar cells. However, there are … Laser‐enhanced contact optimization (LECO) technology is one of the ideal candidates to reduce front contact resistance and metal‐induced recombination of n‐type tunnel oxide‐passivated contact (n‐TOPCon) solar cells. However, there are concerns regarding the reliability of TOPCon modules processed by using LECO, especially in hot and humid conditions. This study explores the degradation of the front and rear sides of TOPCon solar cells under different firing temperatures through highly accelerated temperature and humidity stress testing (HAST) and dry thermal stress testing (DST). It reveals that 700°C is the optimal firing temperature to balance efficiency and stability. The degradation was mainly induced by moisture corrosion during testing. The solar cells showed a notable reduction in PCE, with relative decreases of ∼5.89% after HAST testing. The primary cause of degradation is a considerable increase in recombination within the metallized regions, likely due to contact corrosion. The results of mini module‐level tests demonstrated that rear‐side moisture corrosion was the dominant factor influencing the damp‐heat resistance of TOPCon solar cells. This study provides critical insights into the influence of firing temperatures on the damp‐heat resistance of LECO‐processed TOPCon solar cells and long‐term reliability of TOPCon modules.

Finite element analysis of soldering -induced thermomechanical stress and deformation in multi-busbar interconnected solar cells

2025-06-21

Xu Zhang , W.H. Liu , Shuai Yuan +7 more | Solar Energy

Analysis of the bending and torsion strength of TOPCon solar cells cut by thermal laser separation technology: Advantages for vehicle-integrated photovoltaics

2025-06-20

Daisuke Sato , S. Honda , Terumi Tanimoto +4 more | Solar Energy Materials and Solar Cells

Efficiency improvement and microstructural working principle of LECO on the n-TOPCon rear side of industrial-like TOPCon solar cells

2025-06-19

Stefan Lange , Sina Swatek , Marko Turek +5 more | Solar Energy Materials and Solar Cells

Current distribution unevenness incurred uncertain contact resistivity of silicon heterojunction solar cells

2025-06-19

Guangqing Yang , Zhizhang Xiang , Jiangtao Li +5 more | Solar Energy Materials and Solar Cells

Fabrication and Performance Evaluation of MOV for Voltage Clamping in SSCBs Using Simplified Test Equipment

2025-06-19

M. Chu , Sung-Geun Song , Yong-Gu Kim | The Transactions of the Korean Institute of Power Electronics

Low dislocation density germanium crystal growth by modified heat exchange method

2025-06-19

Alexey Kurus , V.N. Shlegel , L. I. Isaenko | Materials Science and Engineering B

Fabrication of selective boron emitters for TOPCon solar cells using boron-doped amorphous silicon as diffusion source

2025-06-18

Wenhao Chen , Weiqing Liu , Ligang Yuan +3 more | Solar Energy

Comprehensive Analysis and Process Optimization for Wet Chemical Alkaline Edge Isolation for Industrial TOPCon Solar Cells

2025-06-17

Tobias Dannenberg , M. I. Isik , Jan Vollmer +4 more | Progress in Photovoltaics Research and Applications

ABSTRACT Tunnel oxide passivated contact (TOPCon) solar cells are on their way to becoming the next leading cell concept in industrial solar cell manufacturing. However, the efficiency gain compared to … ABSTRACT Tunnel oxide passivated contact (TOPCon) solar cells are on their way to becoming the next leading cell concept in industrial solar cell manufacturing. However, the efficiency gain compared to state‐of‐the‐art PERC cells comes at the cost of additional processes in the manufacturing route. Therefore, it is of utmost importance to increase the profitability of the TOPCon cell architecture by reducing the capital and operating costs as much as possible. In addition to the development of production machines with high throughput and small footprint, the main lever for wet chemical processes is to reduce the consumption of expensive chemicals while maintaining a high process quality. In this work, this goal is pursued with a focus on wet chemical edge isolation. This process is industrially mainly performed in a combination of an inline process for single‐sided glass removal followed by a batch process for rear‐side emitter removal (cluster process). This paper presents our approach to reduce the inline process time without increasing the HF concentration. Furthermore, the rear surface morphology after the alkaline etching at different KOH concentrations with and without a new generation of polishing additive is characterized, and the effect on the implied open‐circuit voltages is shown. The influence of dissolved potassium silicate is also investigated in order to increase the lifetime of the KOH bath. Based on the results, we present TOPCon cell results with efficiencies of about 23.5%, as well as cost of ownership calculations for the most promising approaches and discuss cost of ownership calculations for a US manufacturing scenario.

Novel Nano‐Pyramid/Polish Hybrid Morphology Designed for High‐Efficiency Passivated Contact Solar Cells

2025-06-17

Baochen Liao , Sheng Ma , Reuben J. Yeo +6 more | Progress in Photovoltaics Research and Applications

ABSTRACT In photovoltaic applications, the rear surface morphology of tunnel oxide passivated contact (TOPCon) solar cells plays a critical role in their performance. However, traditional textured and polished surface morphologies … ABSTRACT In photovoltaic applications, the rear surface morphology of tunnel oxide passivated contact (TOPCon) solar cells plays a critical role in their performance. However, traditional textured and polished surface morphologies both have limitations. This study introduces a hybrid nano‐pyramid/polish morphology, combining a nano‐pyramid structure on a polished surface. This new design aims to capitalize on the advantages of both textured and polished surfaces, achieving an optimal balance for TOPCon performance. The balance is achieved through an additional chemical solution treatment process. When applied to TOPCon solar cells, the hybrid structure outperforms both secondary‐textured and polished morphologies in terms of optical absorption, passivation, and contact performance. The nano‐pyramid/polish hybrid achieves a superior balance between light trapping, passivation, and contact quality. Furthermore, the study investigates the impact of rear surface morphology on film blistering, revealing that rougher surfaces are less prone to blistering. This is likely due to more favorable stress distribution in the SiO x /poly‐Si stack, enhancing mechanical stability. These findings demonstrate the compatibility of the hybrid nano‐pyramid/polish morphology with TOPCon solar cells, offering a promising pathway to enhance efficiency. The insights gained may also benefit the development of other high‐performance solar cell technologies, such as heterojunction (HJT) and silicon/perovskite tandem solar cells, advancing industrial photovoltaic applications.

Growth of 4-Inch InP Single-Crystal Wafer Using the VGF-VB Technique

2025-06-17

Hua Wei , Bin Yang , X.L Ye +3 more | ACS Omega

Ideal and Resistive Impurity Parallel-Velocity-Gradient Instability

2025-06-16

Guillermo Cuerva-Lazaro , M. Lesur , Ö. D. Gürcan +4 more | Plasma Physics and Controlled Fusion

Abstract The presence of impurity ions in magnetically confined plasmas can significantly influence micro-instabilities, impacting cross-field transport and ultimately affecting fusion performance. In particular, Parallel Velocity Gradient (PVG) instability, commonly … Abstract The presence of impurity ions in magnetically confined plasmas can significantly influence micro-instabilities, impacting cross-field transport and ultimately affecting fusion performance. In particular, Parallel Velocity Gradient (PVG) instability, commonly observed at the edge of fusion devices and in linear devices, can be strongly influenced by impurities. &#xD;Inspired by the drift-wave models of Hasegawa-Mima and Hasegawa-Watakani, this article develops and examines two distinct fluid models: the ideal impurity-PVG model and the resistive impurity-PVG model. These models aim to investigate the impact of impurities on the key properties the PVG instability, both in the linear and nonlinear regimes. Our findings show that non-negligible impurity concentrations change the growth rates, wave-number ranges, and nonlinear saturations of these instabilities. Notably, the degree of ionization and the relative impurity flow shear can either amplify or mitigate PVG-related turbulence, depending on the impurity and overall plasma conditions. The results underscore the need for a more comprehensive treatment of multi-ion-species plasmas, particularly when impurity fractions cannot be treated as traces.

Role of wafer resistivity in silicon heterojunction solar cells performance: Some insights on carrier dynamics

2025-06-14

Shrestha Bhattacharya , Ashutosh Pandey , S. U. Alam +4 more | Solar Energy

Transmission electron microscopy study on the laser-cutting induced microdefects in silicon heterojunction solar cells

2025-06-14

Xiang Lv , Zechen Hu , Lifei Yang +4 more | Solar Energy Materials and Solar Cells

Unveiling the Hydrogen Diffusion During Degradation of Silicon Solar Cells

2025-06-12

MyeongSeob Sim , Yue Gu , Donghwan Kim +1 more | Energies

We investigated monocrystalline passivated emitter rear contact cells for light- and elevated-temperature-induced degradation. Among the cell performance factors, a short current density results in a significant decrease in the short … We investigated monocrystalline passivated emitter rear contact cells for light- and elevated-temperature-induced degradation. Among the cell performance factors, a short current density results in a significant decrease in the short term. The quantum efficiency is also affected by carrier recombination-active defects, especially in the case of the reference cell, which has a decreased quantum efficiency across the wavelength, unlike the commercial cell. The front side of the cell has a diffuse hydrogen distribution, and it is related to LeTID. We observe how the hydrogen changes during each process and the changes in the profile during the degradation. The hydrogen appears to redistribute within the silicon wafer and saturate at a certain equilibrium state. The hydrogen distribution is correlated with the changes in the lifetime and, finally, short current density. Regeneration occurs depending on the hydrogen concentration within the emitter, and the closer the concentration is to saturation, the less degradation occurs.

The DOS Functions in HD Doping Superlattices of Non-Parabolic Materials, the EFM and the DMR

2025-06-08

| Series on the foundations of natural science and technology

Investigation of the effect of heater electrode heat transfer on heat losses in Czochralski silicon crystal growth based on 3D global numerical simulation

2025-06-01

Changsong Qi , D. Li , Junlan Wang +4 more | Journal of Crystal Growth

Exploring Photovoltaic Potential of Group IV Ternary Si1-x-yGeySnx Alloys in Solar Cells: An In-Depth Numerical Analysis

2025-06-01

Nikita Nikita , Jaspinder Kaur , Preeti Verma +4 more | Journal of Physics and Chemistry of Solids

Effective surface passivation on n-type crystalline silicon of AlOx thin films by thermal atomic layer deposition

2025-06-01

Shiyu Qu , Xiaojie Jia , Lilan Wen +7 more | Journal of Materials Science Materials in Electronics