Design Analysis of a-Si/c-Si HIT Solar Cells

2010 ◽  
Vol 74 ◽  
pp. 131-136 ◽  
Author(s):  
Muhammad Nawaz
Keyword(s):  
Solar Cells ◽  
Computer Aided Design ◽  
Defect Density ◽  
Transport Model ◽  
Design Analysis ◽  
Simulation Software ◽  
Design Tool ◽  
Physical Parameters ◽  
Photogenerated Carrier ◽  
Solar Cell Performance

A theoretical design analysis using numerical two dimensional computer aided design tool (i.e., TCAD) is presented for a-Si/c-Si based heterojunction (HJ) solar cells. A set of optical beam propagation models, complex refractive index models and defect models for a-Si material implemented (in-built) in the simulation software are first evaluated for single (SHJ) and double heterojunction (DHJ) devices. Assessment is further carried out by varying physical parameters of the layer structures such as doping, thickness of the c-Si and a-Si layers, defect density in the a-Si layer and bandgap discontinuity parameter. With varying bandgap discontinuity and using standard transport model in numerical device simulation, HJ solar cell performance is undervalued (η = 19.5%). This is the result of poor photogenerated carrier collection due to the presence of heterojunction at the respective n and p-contacts of the device. Implementing thermionic field emission tunneling model at the heterojunction, we obtained improved performance (η = 24 %) over large range of bandgap discontinuities. Keeping improved efficiency of HJ cell, implementing a step graded a-Si layer, further helps to widen the range of bandgap discontinuity parameter.

Annealing Kinetics of Amorphous Silicon Alloy Solar Cells Made at Various Deposition Rates

2001 ◽  
Vol 664 ◽  
Author(s):  
Baojie Yana ◽  
Jeffrey Yanga ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Frequency ◽  
Room Temperature ◽  
Defect Density ◽  
Very High Frequency ◽  
Solar Cell Performance ◽  
Kinetics Of ◽  
Very High

ABSTRACTA systematic study has been made of the annealing kinetics of amorphous silicon (a-Si) alloy solar cells. The cells were deposited at various rates using H2 dilution with radio frequency (RF) and modified very high frequency (MVHF) glow discharge. In order to minimize the effect of annealing during light soaking, the solar cells were degraded under 30 suns at room temperature to quickly reach their saturated states. The samples were then annealed at an elevated temperature. The J-V characteristics were recorded as a function of annealing time. The correlation of solar cell performance and defect density in the intrinsic layer was obtained by computer simulation. Finally, the annealing activation energy distribution (Ea) was deduced by fitting the experimental data to a theoretical model. The results show that the RF low rate solar cell with high H2 dilution has the lowest Ea and the narrowest distribution, while the RF cell with no H2 dilution has the highest Ea and the broadest distribution. The MVHF cell made at 8Å/s withhigh H2 dilution shows a lower Ea and a narrower distribution than the RF cell made at 3 Å/s, despite the higher rate. We conclude that different annealing kinetics plays an important role in determining the stabilized performance of a-Si alloy solar cells.

scholarly journals Performance Optimization of FD-SOI Hall Sensors Via 3D TCAD Simulations

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2751 ◽  
Author(s):  
Linjie Fan ◽  
Jinshun Bi ◽  
Kai Xi ◽  
Sandip Majumdar ◽  
Bo Li
Keyword(s):  
Performance Optimization ◽  
Computer Aided Design ◽  
Transport Model ◽  
Optimal Structure ◽  
Physical Parameters ◽  
Voltage Sensitivity ◽  
Offset Voltage ◽  
Trade Offs ◽  
Hall Sensors ◽  
Tcad Simulations

This work investigates the behavior of fully depleted silicon-on-insulator (FD-SOI) Hall sensors with an emphasis on their physical parameters, namely the aspect ratio, doping concentration, and thicknesses. Via 3D-technology computer aided design (TCAD) simulations with a galvanomagnetic transport model, the performances of the Hall voltage, sensitivity, efficiency, offset voltage, and temperature characteristics are evaluated. The optimal structure of the sensor in the simulation has a sensitivity of 86.5 mV/T and an efficiency of 218.9 V/WT at the bias voltage of 5 V. In addition, the effects of bias, such as the gate voltage and substrate voltage, on performance are also simulated and analyzed. Optimal structure and bias design rules are proposed, as are some adjustable trade-offs that can be chosen by designers to meet their own Hall sensor requirements.

scholarly journals Silicon Heterojunction Solar Cells with p-Type Silicon Carbon Window Layer

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 402 ◽  
Author(s):  
Chia-Hsun Hsu ◽  
Xiao-Ying Zhang ◽  
Ming Jie Zhao ◽  
Hai-Jun Lin ◽  
Wen-Zhang Zhu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Flow Rate ◽  
Computer Aided Design ◽  
Hydrogenated Amorphous Silicon ◽  
Wavelength Region ◽  
Window Layer ◽  
Solar Cell Performance ◽  
Hydrogenated Amorphous

Boron-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films are deposited using high frequency 27.12 MHz plasma enhanced chemical vapor deposition system as a window layer of silicon heterojunction (SHJ) solar cells. The CH4 gas flow rate is varied to deposit various a-SiC:H films, and the optical and electrical properties are investigated. The experimental results show that at the CH4 flow rate of 40 sccm the a-SiC:H has a high band gap of 2.1 eV and reduced absorption coefficients in the whole wavelength region, but the electrical conductivity deteriorates. The technology computer aided design simulation for SHJ devices reveal the band discontinuity at i/p interface when the a-SiC:H films are used. For fabricated SHJ solar cell performance, the highest conversion efficiency of 22.14%, which is 0.33% abs higher than that of conventional hydrogenated amorphous silicon window layer, can be obtained when the intermediate band gap (2 eV) a-SiC:H window layer is used.

Improved Ambipolar Diffusion Length in a-Si1-xGex:H Alloys for Multi-Junction Solar Cells

1995 ◽  
Vol 377 ◽  
Author(s):  
J. Fölsch ◽  
F. Finger ◽  
T. Kulessa ◽  
F. Siebke ◽  
W. Beyer ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Silicon Germanium ◽  
Diffusion Length ◽  
Defect Density ◽  
Chemical Vapour ◽  
Film Structure ◽  
Ambipolar Diffusion ◽  
Active Layer Thickness ◽  
Solar Cell Performance

ABSTRACTTo prepare hydrogenated amorphous silicon-germanium alloys as low gap material for multi-junction solar cells in plasma enhanced chemical vapour deposition, the well established concept of strong dilution of the process gases with hydrogen has been used. Two different regimes of alloying were found: for low Ge content (x < 0.40) we observe material with low defect density, small Urbach energy and high values of the ambipolar diffusion length. In the regime of high Ge content (x > 0.40) the defect densities and Urbach energies are high and the values of the ambipolar diffusion length low. The transition is accompanied by the appearance of a low-temperature peak in hydrogen effusion experiments indicating a void rich film structure. Material from just above and below the transition zone is used in pin solar cells leading to a much enhanced red response compared with a-Si:H cells. The differences seen in the material quality are mirrored in the solar cell properties. By carefully adjusting the active layer thickness material with low diffusion length shows also reasonable solar cell performance.

On the Assessment of Temperature Dependence of 10 - 20 kV 4H-SiC IGBTs Using TCAD

2013 ◽  
Vol 740-742 ◽  
pp. 1085-1088 ◽  
Author(s):  
Muhammad Nawaz ◽  
Filippo Chimento
Keyword(s):  
Temperature Dependence ◽  
Computer Aided Design ◽  
Carrier Mobility ◽  
Minority Carrier ◽  
Life Time ◽  
Bipolar Transistors ◽  
Design Tool ◽  
Physical Parameters ◽  
Aided Design ◽  
Carrier Life Time

This paper addresses and evaluates the temperature dependence performance of silicon carbide (4H-SiC) based insulated gate bipolar transistors (IGBTs) using two dimensional numerical computer aided design tool (i.e., Atlas TCAD from Silvaco). Using identical set of device physical parameters (doping, thicknesses), simulated structure was first caliberated with the experimental data. A minority carrier life time in the drift layer of 1.0 – 1.6 µs and contact resistivity of 0.5 - 1.0 x 10-4 Ω-cm2 produces a close match with the experimental device. A set of n type IGBT structures were then numerically simulated to extract the conduction losses for various blocking voltage classes. An on-resistance first decays with temperature (i.e., increased in ionization level, and increase in minority carrier life time), stays nearly constant with further increase in the temperature (may be all carriers are now fully ionized and increase in carrier life time is compensated with decrease in the carrier mobility) and finally increases linearly with temperature (>450 oC) due to decrease in the carrier mobility. Compared with Si based IGBTs, numerical simulation predicts lower VCEON and RON values for 4H-SiC based IGBTs for higher voltage classes and hence potential for achieving smaller conduction losses for SiC based IGBTs.

scholarly journals Passivation of InP solar cells using large area hexagonal-BN layers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Vidur Raj ◽  
Dipankar Chugh ◽  
Lachlan E. Black ◽  
M. M. Shehata ◽  
Li Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Surface Passivation ◽  
Defect Density ◽  
Hexagonal Boron Nitride ◽  
Cell Structure ◽  
Chemical Vapor ◽  
Large Area ◽  
Solar Cell Performance ◽  
Passivation Layers

AbstractSurface passivation is crucial for many high-performance solid-state devices, especially solar cells. It has been proposed that 2D hexagonal boron nitride (hBN) films can provide near-ideal passivation due to their wide bandgap, lack of dangling bonds, high dielectric constant, and easy transferability to a range of substrates without disturbing their bulk properties. However, so far, the passivation of hBN has been studied for small areas, mainly because of its small sizes. Here, we report the passivation characteristics of wafer-scale, few monolayers thick, hBN grown by metalorganic chemical vapor deposition. Using a recently reported ITO/i-InP/p+-InP solar cell structure, we show a significant improvement in solar cell performance utilizing a few monolayers of hBN as the passivation layer. Interface defect density (at the hBN/i-InP) calculated using C–V measurement was 2 × 1012 eV−1cm−2 and was found comparable to several previously reported passivation layers. Thus, hBN may, in the future, be a possible candidate to achieve high-quality passivation. hBN-based passivation layers can mainly be useful in cases where the growth of lattice-matched passivation layers is complicated, as in the case of thin-film vapor–liquid–solid and close-spaced vapor transport-based III–V semiconductor growth techniques.

Critical Assessment of Sub-Bandgap Primary Photocurrent in a-Si:H Based Solar Cells.

1991 ◽  
Vol 219 ◽  
Author(s):  
T. X. Zhou ◽  
S. S. Hegedus ◽  
C. M. Fortmann
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Defect Density ◽  
Critical Assessment ◽  
Cell Performance ◽  
Significant Discrepancy ◽  
Solar Cell Performance ◽  
Before And After ◽  
Degree Of Degradation

ABSTRACTThe sub-bandgap primary photocurrent and the solar cell performance of a-Si:H p-i-n devices have been studied before and after light induced degradation. The results indicate significant discrepancy between the two methods when used to estimate the degree of degradation and the defect density in the i-layers. A preliminary explanation is proposed.

scholarly journals Influence of Defect States and Thickness of Interface Layer On High Efficiency of c-Si/a-Si:H Heterojunction Solar Cells With Higher Bandgap a-Si:H(p) Layer By Simulation

2021 ◽  
Author(s):  
Venkanna Kanneboina
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Defect Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Interface Layer ◽  
Open Circuit ◽  
Defect States ◽  
Solar Cell Performance ◽  
Heterojunction Solar Cells

Abstract This paper presents the influence of defect states and thickness of interface layer on high efficiency of c-Si/a-Si:H heterojunction solar cells with higher bandgap emitter a-Si:H(p) layer by AFORSHET simulation tool. At first, the performance of Ag/ZnO/a-Si:H(p)/ a-Si:H(i)/ c-Si(n)/ a-Si:H(i)/ a-Si:H(n)/Ag heterojunction solar cells was studied by altering the thickness of a-Si:H(p) and a-Si:H(i) layers. The best values of open circuit voltage (Voc) (764.8 mV), short circuit current density (Jsc) (43.15 mA/cm2), fill factor (FF) (85.71) and efficiency(ɳ) (28.28%) were obtained at 3 nm of a-Si:H(p) and a-Si:H(i) layer. In the same structure, c-Si(n) interface was introduced in between c-Si(n) and a-Si:H(i) layer. It is found that the solar cell performance was not changed by varying defect density from 109-1014 cm-3 for thin (5 and 10 nm) interface layer and estimated values are 761.7 mV, 38.83 mA/cm2, 86.09%, 25.46% correspond to Voc, Jsc, FF, ɳ respectively. For very thick interface layer, defect density has shown huge impact on the device performance. At 1 µm, the Voc, FF and ɳ values have been changed from 760.2 to 653.2 mV, 85.9 to 80.76% and 22.94 to 18.47% for the defect density of 109 to 1014 cm-3 respectively.

scholarly journals Analysis of The Efficiency In Sb2Se3 Thin-Film Solar Cells Using Alternative Buffer Layers In n-p and n-i-p Structures By Numerical Simulation.

2021 ◽  
Author(s):  
F Ayala-Mato ◽  
O Vigil-Galán ◽  
Maykel Courel ◽  
M. M. Nicolás-Marín
Keyword(s):  
Numerical Simulation ◽  
Solar Cells ◽  
Solar Cell ◽  
Defect Density ◽  
Hole Transport ◽  
Inorganic Materials ◽  
Band Alignment ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Solar Cell Performance

Abstract Antimony Sulfide (Sb2Se3) Solar Cells are considered a promising emerging photovoltaic devices technology. However, the best reported experimental efficiency (9.2%) is well below the theoretical limit of 30%. In this research is demonstrated, by numerical simulation, that using different buffer or electron transport layers (ETL) and device structures (n-p or n-i-p) can significantly increase the solar cell performance. The study is based on two underlying considerations: the use of inorganic materials to facilitate the manufacturing process and the analysis of the simulation parameters that adjust to the experimental conditions in which the cells can be processed. In the n-p structures, the use of single layers and bilayers as ETL was evaluated and the possible mechanism that explain the electrical parameters of the solar cell were discussed. Especial attention was made in the role of interfacial state density and band alignment in the ETL/Sb2Se3 interface. In addition, the n-i-p structure was studied by adding a hole transport layer (HTL). An improvement in open circuit voltage (Voc) is observed compared with n-p structure. Finally, the behavior of Voc and efficiency vs thickness of the ETL and Sb2Se3 layers was analyzed. The results show that using alternative ETLs a significant improve in Voc and efficiency could be achieved for n-p and n-i-p structures. After thickness optimization and taking account a moderate interface defect density, values of Voc and efficiency higher than 600 mV and 15 % were respectively obtained.

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