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.

Hydrogenated amorphous silicon–germanium thin films with a narrow band gap for silicon-based solar cells

2011 ◽  
Vol 11 (1) ◽  
pp. S50-S53 ◽  
Author(s):  
Chao-Chun Wang ◽  
Chueh-Yang Liu ◽  
Shui-Yang Lien ◽  
Ko-Wei Weng ◽  
Jung-Jie Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Silicon Germanium ◽  
Narrow Band ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Based ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

Stability Studies of Hydrogenated Amorphous Silicon Alloy Solar Cells Prepared with Hydrogen Dilution

1994 ◽  
Vol 336 ◽  
Author(s):  
J. Yang ◽  
X. Xu ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Deposition Temperature ◽  
Hydrogenated Amorphous Silicon ◽  
Open Circuit ◽  
Solar Cell Performance ◽  
Silicon Alloy ◽  
Before And After ◽  
Photovoltaic Characteristics ◽  
Hydrogenated Amorphous

ABSTRACTWe have fabricated hydrogenated amorphous silicon alloy solar cells using hydrogen dilutions at 175 °C and 300 °C, and obtained improved photovoltaic characteristics in both the initial and degraded states for the highly diluted cells; both the fill factor and the open-circuit voltage exhibit higher values before and after light soaking. Infrared analyses reveal that for a given deposition temperature the amount of bonded hydrogen has similar concentrations between the high and low hydrogen diluted samples. Optical Modelling shows a 20 MeV difference in their optical bandgap. Defect densities obtained from constant photocurrent measurements give similar values for a given deposition temperature both before and after light soaking, inconsistent with solar cell performance.

Hydrogenated amorphous silicon germanium by Hot Wire CVD as an alternative for microcrystalline silicon in tandem and triple junction solar cells

2014 ◽  
Vol 1666 ◽  
Author(s):  
L.W. Veldhuizen ◽  
Y. Kuang ◽  
N.J. Bakker ◽  
C.H.M. van der Werf ◽  
S.-J. Yun ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Silicon Germanium ◽  
Short Circuit ◽  
Hydrogenated Amorphous Silicon ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

ABSTRACTWe study hydrogenated amorphous silicon germanium (a-SiGe:H) deposited by HWCVD for the use as low band gap absorber in multijunction junction solar cells. We deposited layers with Tauc optical band gaps of 1.21 to 1.56 eV and studied the hydrogen bonding with FTIR for layers that were deposited at several reaction pressures. For our reaction conditions, we found an optimal reaction pressure of 38 µbar. The material that is obtained under these conditions does not meet all device quality requirements for a-SiGe:H, which is, as we hypothesize, caused by the presence of He that is used to dilute the GeH4 source gas. We present an initial single junction n-i-p solar cell with a Tauc optical band gap of 1.45 eV and a short circuit current density of 18.7 mA/cm2.

Crystalline Silicon Surface Passivation by Pecv-Deposited Hydrogenated Amorphous Silicon Oxide Films [a-SiOx:H]

2007 ◽  
Vol 989 ◽  
Author(s):  
Thomas Mueller ◽  
Wolfgang Duengen ◽  
Reinhart Job ◽  
Maximilian Scherff ◽  
Wolfgang Fahrner
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Thermal Annealing ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Window Layer ◽  
Effective Lifetime ◽  
Si Solar Cells ◽  
Hydrogenated Amorphous

AbstractIn the research field of crystalline silicon (c-Si) solar cells, electronic surface passivation has been recognized as a crucial step to achieve high conversion efficiencies. The main issue of this article is to analyze the surface passivation properties of both, n-type and p-type crystalline silicon wafers by hydrogenated amorphous silicon sub oxide [a-SiOx:H] films the for use in hetero-junction (a-Si/c-Si) solar cells. A window layer is obtained with a certain fraction of oxygen in the a-SiOx:H layers.The a-SiOx:H films were deposited by decomposition of silane, carbon dioxide and hydrogen as source gases using plasma enhanced chemical vapor deposition (PECVD). Films with varying deposition parameters such as gas flow ratio (oxygen fraction) and plasma frequency (13.56, 70.0 and 110.0 MHz) are compared.To determine the passivation quality of the a-SiOx:H films, microwave-detected photo conductance decay (µ-PCD) provides a contactless measurement of the effective recombination lifetime of free carriers. The film compositions and also the changes in the microscopic structure of the amorphous network upon thermal annealing are studied using Raman spectroscopy and optical profiling techniques.The Raman spectra reveal the generation of Si-(OH)x and Si-O-Si bonds after thermal annealing in the layers, leading to a higher effective lifetime, as it reduces the defect absorption of the sub oxides.For n-type FZ material, lifetime values as high as 1650 µs are obtained, resulting in a surface recombination velocity Seff < 9.5 cm/s.

Hydrogenated Amorphous Silicon Based Solar Cells: Optimization Formalism and Numerical Algorithm

2009 ◽  
Vol 1153 ◽  
Author(s):  
Anatoli Shkrebtii ◽  
Yuriy Kryuchenko ◽  
Anaroliy Sachenko ◽  
Igor Sokolovskyi ◽  
Franco Gaspari
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Amorphous Film ◽  
Solar Cell Performance ◽  
Transparent Conducting ◽  
Silicon Based ◽  
Hydrogenated Amorphous

AbstractThin film hydrogenated amorphous silicon (a-Si:H) is widely used in photovoltaics. In order to get the best possible performance of the a-Si:H solar cells it is important to optimize the amorphous film and solar cells in terms their parameters such as mobility gap, p-, i- and n-layer doping levels, electron and hole lifetime and their mobilities, resistance of p-, i- and n-layers, contact grid geometry and parameters of the transparent conducting and antireflecting layers, and others. To maximize thin a-Si:H film based solar cell performance we have developed a general numerical formalism of photoconversion, which takes into account all the above parameters for the optimization. Application of the formalism is demonstrated for typical a-Si:H based solar cells before Staebler-Wronski (SW) light soaking effect. This general formalism is not limited to a-Si:H based systems only, and it can be applied to other types of solar cells as well.

Radial Junction Architecture: A New Approach to Stable and Highly Efficient Silicon Thin Film Solar Cells

2015 ◽  
Vol 1770 ◽  
pp. 73-78 ◽  
Author(s):  
S. Misra ◽  
M. Foldyna ◽  
I. Florea ◽  
L. Yu ◽  
P. Roca i Cabarrocas
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Light Trapping ◽  
Short Circuit ◽  
Power Conversion ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Thin Film ◽  
Hydrogenated Amorphous

ABSTRACTIncorporation of properly designed nanostructures in solar cells improves light trapping and consequently their power conversion efficiencies. Due to its unique structure, a silicon nanowire (SiNW) matrix provides excellent light trapping and thus offers a promising approach for cost-effective, stable and efficient silicon thin film photovoltaics. Moreover, by decoupling the light absorption and carrier collection directions, radial junction solar cells built around the SiNWs allow the use of very thin active layers. As a matter of fact, radial PIN junctions with 9.2% power conversion efficiency have already been demonstrated on glass substrates with only 100 nm thick intrinsic hydrogenated amorphous silicon layers. The most straightforward way to further improve the short circuit current density is to use an active layer with a lower band gap. In this work, the performances of devices with two different low band gap materials, e.g., hydrogenated microcrystalline silicon (μc-Si:H) and hydrogenated amorphous silicon germanium alloy (a-SiGe:H) are presented. To the best of our knowledge, this is the first demonstration of a-SiGe:H radial junction solar cell.

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