Hydrogenated Amorphous Silicon Germanium Alloy for Stable Solar Cells

1994 ◽  
Vol 336 ◽  
Author(s):  
A. Terakawa ◽  
M. Shima ◽  
K. Sayama ◽  
H. Tarui ◽  
H. Nishiwaki ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Silicon Germanium ◽  
Defect Density ◽  
Characteristic Energy ◽  
Solar Cell Performance ◽  
Germanium Content ◽  
Junction Solar Cell ◽  
Degradation Ratio ◽  
Double Junction

ABSTRACTThe film properties and solar cell performance of a-SiGe:H samples with the same optical gap and different combinations of hydrogen content (CH) and germanium content (CGe) have been compared. The optimum composition for the initial properties, such as the tail characteristic energy, defect density and conversion efficiency of the solar cell, was determined, and the differences could be explained by the difference in H bonding configuration. The degradation ratio of the conversion efficiency becomes larger in higher CH samples. This suggests that hydrogen or Si-H2 participates in light-induced degradation. As a result, the optimum CH for an efficient solar cell is believed to shift to the lower CH region after light soaking. Based on these findings, the stabilized conversion efficiency of 3.3% under red light (γ>650nm) for an a-SiGe:H single-junction solar cell (1cm2) and 10.6% under lsun light for an a-Si/a-SiGe double-junction stacked solar cell (1cm2) have been achieved. The degradation ratio is only 8.6% for the double-junction solar cell.

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.

scholarly journals Perovskite/CIGS Spectral Splitting Double Junction Solar Cell with 28% Power Conversion Efficiency

iScience ◽  
2020 ◽  
Vol 23 (12) ◽  
pp. 101817
Author(s):  
Motoshi Nakamura ◽  
Keishi Tada ◽  
Takumi Kinoshita ◽  
Takeru Bessho ◽  
Chie Nishiyama ◽  
...  
Keyword(s):  
Solar Cell ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Power Conversion ◽  
Junction Solar Cell ◽  
Spectral Splitting ◽  
Double Junction

scholarly journals Antireflection Improvement and Junction Quality Optimization of Si/PEDOT:PSS Solar Cell with the Introduction of Dopamine@Graphene

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5986
Author(s):  
Tao Chen ◽  
Hao Guo ◽  
Leiming Yu ◽  
Tao Sun ◽  
Anran Chen ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrochemical Impedance Spectra ◽  
Solar Cell Performance ◽  
Photovoltaic Conversion ◽  
Photovoltaic Conversion Efficiency

Si/PEDOT: PSS solar cell is an optional photovoltaic device owing to its promising high photovoltaic conversion efficiency (PCE) and economic manufacture process. In this work, dopamine@graphene was firstly introduced between the silicon substrate and PEDOT:PSS film for Si/PEDOT: PSS solar cell. The dopamine@graphene was proved to be effective in improving the PCE, and the influence of mechanical properties of dopamine@graphene on solar cell performance was revealed. When dopamine@graphene was incorporated into the cell preparation, the antireflection ability of the cell was enhanced within the wavelength range of 300~450 and 650~1100 nm. The enhanced antireflection ability would benefit amount of the photon-generated carriers. The electrochemical impedance spectra test revealed that the introduction of dopamine@graphene could facilitate the separation of carriers and improve the junction quality. Thus, the short-circuit current density and fill factor were both promoted, which led to the improved PCE. Meanwhile, the influence of graphene concentration on device performances was also investigated. The photovoltaic conversion efficiency would be promoted from 11.06% to 13.15% when dopamine@graphene solution with concentration 1.5 mg/mL was applied. The achievements of this study showed that the dopamine@graphene composites could be an useful materials for high-performance Si/PEDOT:PSS solar cells.

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 Optimization of the InGaP Top Junction of Triple Junction Solar Cell for Spatial Application

2019 ◽  
Vol 14 (1) ◽  
pp. 1-5
Author(s):  
Victor De Rezende Cunha ◽  
Daniel Neves Micha ◽  
Rudy Massami Sakamoto Kawabata ◽  
Luciana Dornelas Pinto ◽  
Mauricio Pamplona Pires ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Current Density ◽  
Triple Junction ◽  
Short Circuit ◽  
Active Material ◽  
Multiple Quantum Well ◽  
Electrical Current ◽  
Multiple Quantum ◽  
Junction Solar Cell

Electrical current mismatching is a well-known limitation of triple junction solar cells that lowers the final conversion efficiency. Several solutions have been proposed to face this issue, including the insertion of a multiple quantum well structure as the intermediate junction’s active material. With a better matching in the current among the junctions, the total current increases, thus modifying the working conditions of the overall device. In this way, the InGaP top junction needs to be optimized to such new condition. In this work, numerical simulations were carried out aiming the enlargement of the electrical current density of an InGaP pn junction to achieve the proper current matching in triple junction solar cell for spatial applications. The optimized structure has been grown in a GaAs substrate and characterized as a single junction solar cell. Although the measured short circuit current density and conversion efficiency are still well below the theoretically predicted values, processing improvement should lead to adequate cell performance.

Mechanically Stacked GaAs/GaInAsP Dual-Junction Solar Cell with High Conversion Efficiency of More than 31%

2005 ◽  
Vol 44 (No. 31) ◽  
pp. L988-L990 ◽  
Author(s):  
Takashi Yamada ◽  
Akihiro Moto ◽  
Yasuhiro Iguchi ◽  
Mitsuo Takahashi ◽  
So Tanaka ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
High Conversion ◽  
High Conversion Efficiency ◽  
Junction Solar Cell

Effects of Ga Compositional Grading on CIGS Electronic Properties Relevant to Solar Cell Performance

2009 ◽  
Vol 1165 ◽  
Author(s):  
JinWoo Lee ◽  
Jeroen K.J. van Duren ◽  
Alex Pudov ◽  
Miguel Contreras ◽  
David J. Cohen
Keyword(s):  
Solar Cell ◽  
Minority Carrier ◽  
Defect Density ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
Free Hole ◽  
Deep Acceptor ◽  
Free Carrier Density ◽  
Carrier Collection ◽  
Compositional Grading

AbstractTransient photocurrent (TPI) and photocapacitance (TPC) spectroscopy have been applied to a set of compositional graded CuIn1-xGaxSe2 (CIGS) solar cell devices deposited by the vacuum co-evaporation method at the National Renewable Energy Laboratory. These measurements provide a spectral map of the optically induced release of carriers for photon energies from below 1 eV to 2 eV. By comparing the two types of spectra one can distinguish majority from minority carrier processes and they clearly reveal a higher degree of minority carrier collection for devices in which the Ga fraction increased monotonically with distance from the junction. This agrees with notions of how compositional grading improves overall cell performance. Minority carrier collection was even more strongly enhanced in sample devices incorporating v-shaped Ga-grading. Spatial profiles of the free hole carrier densities and deep acceptor concentrations were examined using drive-level capacitance profiling (DLCP). In the compositionally graded sample devices we found that the free carrier density decreased and that defect density increased with increasing Ga fraction toward back contact.

Chemical Composition Dependence of Cu2ZnSnS4 Absorbers Fabricated by Sulfurization of Thermal Evaporated Metal Precursors and Solar Cell Performance

2015 ◽  
Vol 1738 ◽  
Author(s):  
Liyuan Zhang ◽  
Sreejith Karthikeyan ◽  
Mandip J. Sibakoti ◽  
Stephen A. Campbell
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Chemical Composition ◽  
Conversion Efficiency ◽  
Small Deviation ◽  
Short Circuit ◽  
Cell Performance ◽  
Czts Thin Film ◽  
Solar Cell Performance

ABSTRACTWe investigate the synthesis of kesterite Cu2ZnSnS4 (CZTS) thin films using thermal evaporation from copper, zinc and tin pellets and post-annealing in a sulfur atmosphere. The effects of chemical composition were studied both on the absorber layer properties and on the final solar cell performance. It is confirmed that CZTS thin film chemical composition affects the carrier concentration profile, which then influences the solar cell properties. Solar cells using a CZTS thin film with composition ratio Cu/(Zn+Sn) = 0.87, and Zn/Sn = 1.24 exhibited an open-circuit voltage of 483 mV, a short-circuit current of 14.54 mA/cm2, a fill factor of 37.66 % and a conversion efficiency of 2.64 %. Only a small deviation from the optimal chemical composition can drop device performance to a lower level, which confirms that the CZTS solar cells with high conversion efficiency existed in a relatively narrow composition region.

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