Effect of Buffer Structure on the Performance of a-Si:H/a-Si:H Tandem Solar Cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
C.H. Hsu ◽  
C.Y. Lee ◽  
P.H. Cheng ◽  
C.K. Chuang ◽  
C.C. Tsai
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Short Circuit ◽  
Hydrogenated Amorphous Silicon ◽  
Open Circuit ◽  
Buffer Layers ◽  
Single Junction ◽  
Bottom Cell ◽  
Hydrogenated Amorphous

ABSTRACTThe study focuses on the influence of the hydrogenated amorphous silicon carbide (a-SiC:H) buffer layer in hydrogenated amorphous silicon (a-Si:H) single-junction and tandem thin-film solar cells. By increasing the undoped a-SiC:H buffer layer thickness from 6nm to 12nm, the JSC in single-junction cell was significantly improved, and the efficiency was increased by 4.5%. The buffer layer also effectively improves the efficiency of the a-Si:H/a-Si:H tandem cells by 7% as a result of the increase in open-circuit voltage (VOC) and short-circuit current (JSC). Although the bottom cell absorbs less short-wavelength photons, the wider-bandgap doped and buffer layers were still necessary for improving the cell efficiency. Presumably, this is because these wider-bandgap layers allow more photons to reach the bottom cell. Also, they can reduce interface recombination.

scholarly journals Numerical Design of Ultrathin Hydrogenated Amorphous Silicon-Based Solar Cell

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
F. X. Abomo Abega ◽  
A. Teyou Ngoupo ◽  
J. M. B. Ndjaka
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Theoretical Work ◽  
Silicon Based ◽  
The Impact ◽  
Hydrogenated Amorphous

Numerical modelling is used to confirm experimental and theoretical work. The aim of this work is to present how to simulate ultrathin hydrogenated amorphous silicon- (a-Si:H-) based solar cells with a ITO BRL in their architectures. The results obtained in this study come from SCAPS-1D software. In the first step, the comparison between the J-V characteristics of simulation and experiment of the ultrathin a-Si:H-based solar cell is in agreement. Secondly, to explore the impact of certain properties of the solar cell, investigations focus on the study of the influence of the intrinsic layer and the buffer layer/absorber interface on the electrical parameters ( J SC , V OC , FF, and η ). The increase of the intrinsic layer thickness improves performance, while the bulk defect density of the intrinsic layer and the surface defect density of the buffer layer/ i -(a-Si:H) interface, respectively, in the ranges [109 cm-3, 1015 cm-3] and [1010 cm-2, 5 × 10 13  cm-2], do not affect the performance of the ultrathin a-Si:H-based solar cell. Analysis also shows that with approximately 1 μm thickness of the intrinsic layer, the optimum conversion efficiency is 12.71% ( J SC = 18.95   mA · c m − 2 , V OC = 0.973   V , and FF = 68.95 % ). This work presents a contribution to improving the performance of a-Si-based solar cells.

Effect of the Quantum Size Effect on the Performance of Solar Cells with a Silicon Nanowire Array Embedded in SiO2

2012 ◽  
Vol 1439 ◽  
pp. 145-150
Author(s):  
Yasuyoshi Kurokawa ◽  
Shinya Kato ◽  
Yuya Watanabe ◽  
Akira Yamada ◽  
Makoto Konagai ◽  
...  
Keyword(s):  
Solar Cells ◽  
Size Effect ◽  
Amorphous Silicon ◽  
Silicon Nanowire ◽  
Nanowire Array ◽  
Hydrogenated Amorphous Silicon ◽  
Open Circuit ◽  
Quantum Size Effect ◽  
Quantum Size ◽  
Hydrogenated Amorphous

ABSTRACTThe electrical characteristics of silicon nanowire (SiNW) solar cells with p-type hydrogenated amorphous silicon oxide (Eg=1.9 eV)/n-type SiNWs embedded in SiO2/n-type hydrogenated amorphous silicon (Eg=1.7 eV) structure have been investigated using a two-dimensional device simulator with taking the quantum size effects into account. The average bandgap of a SiNW embedded in SiO2 increased from 1.15 eV to 2.71 eV with decreasing the diameter from 10 nm to 1 nm due to the quantum size effect. It should be noted that under the sunlight with AM1.5G the open-circuit voltage (Voc) of SiNW solar cells also increased to 1.54 V with decreasing the diameter of the SiNWs to 1 nm. This result suggests that it is possible to enhance the Voc by the quantum size effect and a SiNW is a promising material for the all silicon tandem solar cells.

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.

scholarly journals Temperature-Dependent Open-Circuit Voltage Measurements and Light-Soaking in Hydrogenated Amorphous Silcon Solar Cells

2005 ◽  
Vol 862 ◽  
Author(s):  
Jianjun Liang ◽  
E. A. Schiff ◽  
S. Guha ◽  
B. Yan ◽  
J. Yang
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Room Temperature ◽  
Open Circuit Voltage ◽  
Hydrogenated Amorphous Silicon ◽  
Open Circuit ◽  
Illumination Intensity ◽  
Temperature Dependent ◽  
Defect Generation ◽  
Hydrogenated Amorphous

AbstractWe present temperature-dependent measurements of the open-circuit voltage VOC(T) in hydrogenated amorphous silicon nip solar cells prepared at United Solar. At room-temperature and above, VOC measured using near-solar illumination intensity differs by as much as 0.04 V for the as-deposited and light-soaked states; the values of VOC for the two states converge below 250 K. Models for VOC based entirely on recombination through deep levels (dangling bonds) do not account for the convergence effect. The convergence is present in a model that assumes the recombination traffic in the as-deposited state involves only bandtails, but which splits the recombination traffic fairly evenly between bandtails and defects for the light-soaked state at room-temperature. Recombination mechanisms are important in understanding light-soaking, and the present results are inconsistent with at least one well-known model for defect generation.

Buffer Layers for Narrow Bandgap A-SIGE Solar Cells

1999 ◽  
Vol 557 ◽  
Author(s):  
X. B. Liao ◽  
J. Walker ◽  
X. Deng
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Hydrogenated Amorphous Silicon ◽  
Absorber Layer ◽  
Buffer Layers ◽  
Narrow Bandgap ◽  
Interface Layers ◽  
Hydrogenated Amorphous

AbstractIn high efficiency narrow bandgap (NBG) a-SiGe solar cells, thin buffer layers of unalloyed hydrogenated amorphous silicon (a-Si) are usually used at the interfaces between the a-SiGe intrinsic layer and the doped layers. We investigated the effect of inserting additional a-SiGe interface layers between these a-Si buffer layers and the a-SiGe absorber layer. We found that such additional interface layers increase solar cell VOC and FF sizably, most likely due to the reduction or elimination of the abrupt bandgap discontinuity between the a-SiGe absorber layer and the a-Si buffer layers. With these improved narrow bandgap solar cells incorporated into the fabrication of triple-junction a-Si based solar cells, we obtained triple cells with initial efficiency of 10.6%.

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.

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