Degradation Mechanism of III-V Triple Junction Solar Cells Analyzed Using Step Stress Tests

2013 ◽  
Vol 284-287 ◽  
pp. 281-286 ◽  
Author(s):  
Hwen Fen Hong ◽  
Jin Wei ◽  
Mei Hui Chiang ◽  
Zun Hao Shih ◽  
Wu Yih Uen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Triple Junction ◽  
Fill Factor ◽  
Degradation Mechanism ◽  
Depletion Region ◽  
Open Circuit ◽  
Protective Film ◽  
Stress Tests ◽  
Accelerated Degradation ◽  
Recombination Current

We analyzed the degradation mechanism of GaInP/GaInAs/Ge triple junction solar cells without coating any protective film. Gradual degradation in the dark and light I-V characteristics of the solar cells were observed after the step stress accelerated degradation tests (SSADT) were conducted on these devices sequentially at 90, 110, 130 and 150°Cfor 25, 55, 85 and 135 hours, respectively. The recombination current in the depletion region at the chip perimeter of solar cells, resulting in the decrease of open-circuit voltage (VOC), fill factor (FF) and efficiency, is suggested to be the important degradation mechanism for GaInP/GaInAs/Ge triple junction solar cells.

scholarly journals Damp-Heat Induced Performance Degradation for InGaP/GaAs/Ge Triple-Junction Solar Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hwen-Fen Hong ◽  
Tsung-Shiew Huang ◽  
Wu-Yih Uen ◽  
Yen-Yeh Chen
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Conversion Efficiency ◽  
Triple Junction ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Energy Conversion Efficiency ◽  
Open Circuit

We performed accelerated tests on sealed and nonsealed InGaP/InGaAs/Ge triple-junction (TJ) solar cells in a complex high temperature and high humidity environment and investigated the electrical properties over time. The degradation of energy conversion efficiency in nonsealed cells was found to be more serious than that in sealed cells. The short-circuit current (ISC), open-circuit voltage (VOC), and fill factor (FF) of sealed cells changed very slightly, though the conversion efficiency decreased 3.6% over 500 h of exposure. This decrease of conversion efficiency was suggested to be due to the deterioration of silicone encapsulant. TheISC,VOC, and FF of nonsealed cells decreased with increasing exposure time. By EL and SEM analysis, the root causes of degradation can be attributed to the damage and cracks near the edge of cells induced by the moisture ingress. It resulted in shunt paths that lead to a deterioration of the conversion efficiency of solar cell by increasing the leakage current, as well as decreasing open-circuit voltage and fill factor of nonsealed solar cells.

The Effects of Dopant Profiles on the Device Parapmetrs of p-i-n and n-i-p a-Si Solar Cells

1986 ◽  
Vol 70 ◽  
Author(s):  
F. R. Jeffrey ◽  
G. D. Vernstrom ◽  
M. Weber ◽  
K. A. Epstein
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Surface Recombination ◽  
Open Circuit ◽  
Response Data ◽  
Si Solar Cells ◽  
Recombination Current ◽  
Dopant Profiles

ABSTRACTwe have studied the effects of intrinsic layer dopant profiles on the open circuit voltage and fill factor of p-i-n and n-i-p solar cells. Data is presented showing that boron profiling into the i-layer is responsible for the commonly observed difference in open circuit voltage between p-i-n and n-i-p devices. As only a shallow profile is required to produce this effect, it is proposed that the lower Voc samples are being limited by surface recombination at the p/i interface and that the boron profile reduces this recombination current. The fill factor for devices illuminated through the n+ layer is shown to be very sensitive to the depth of a boron profile, yet not so sensitive to the profile concentration. A maximum occurs for a profile penetrating slightly more than half way through the cell. Spectral response data clearly shows a shifting of high collection from the back to the front of the cell.

Effect of the Impurity Concentration of a-Si:H on the Properties of a-Si:H/c-S Heterojunction Solar Cells

2012 ◽  
Vol 485 ◽  
pp. 461-464
Author(s):  
Lan E Luo ◽  
Chun Liang Zhong
Keyword(s):  
Solar Cells ◽  
Doping Level ◽  
Impurity Concentration ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Depletion Region ◽  
Open Circuit ◽  
High Doping Level ◽  
Heterojunction Solar Cells

Effect of the impurity concentration of a-Si:H, ND2, on the properties of a-Si:H/c-S heterojunction solar cells is studied by a set of AMPS simulations. The results show that the short-circuit current almost not depends on ND2. At a low doping level, the electric field redistributes in the c-Si depletion region and the barrier at the heterojunction interface hinders the collection of photogenerated holes. It results in an enhanced recombination inside the c-Si depletion region and the S-Shaped J-V characteristics. As a sequence, the open-circuit voltage VOC and the fill factor FF decreases with ND2 decreasing. However, at a high doping level, VOC and FF is independent on ND2 as the diffusion potential is mainly accommodated in the c-Si. So the efficiency increases with ND2 increasing at a low doping level, and then is independent on ND2 at a high doping level. Therefore, to improve the properties of a-Si:H/c-Si heterojunction solar cells, the a-Si:H layer should be highly doped.

Microcrystalline (Si,Ge):H Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal
Keyword(s):  
Solar Cells ◽  
Buffer Layer ◽  
Quantum Efficiency ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Cell Structure ◽  
Open Circuit ◽  
Base Layer ◽  
Ecr Plasma

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.

Kinetics of Light-Induced Effects in Mixed-Phase Hydrogenated Silicon Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Guozhen Yuea ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Equivalent Circuit Model ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Initial Increase ◽  
Soaking Time ◽  
Hydrogenated Silicon ◽  
Kinetics Of

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.

scholarly journals GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Low Temperature ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Metal Line ◽  
Solar Simulator ◽  
Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

Study of Photoelectrochemical Solar Cell Using WSe2 Crystal

2013 ◽  
Vol 665 ◽  
pp. 330-335 ◽  
Author(s):  
Ripal Parmar ◽  
Dipak Sahay ◽  
R.J. Pathak ◽  
R.K. Shah
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Open Circuit ◽  
Cell Parameters ◽  
Photoelectrochemical Solar Cell ◽  
Photoelectrochemical Solar Cells

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.

scholarly journals SCAPS Simulation on P3HT:Graphene Nanocomposites Based Bulk-Heterojunction Organic Solar Cells

2019 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Nur Shakina Mohd Shariff ◽  
Puteri Sarah Mohamad Saad ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Fill Factor ◽  
Bulk Heterojunction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Simulation Software ◽  
Capacitance Voltage

There has been an increasing interest towards organic solar cells after the discovery of conjugated polymer and bulk-heterojunction concept. Eventhough organic solar cells are less expensive than inorganic solar cells but the power conversion energy is still considered low. The main objective of this research is to investigate the effect of the P3HT’s thickness and concentration towards the efficiency of the P3HT:Graphene solar cells. A simulation software that is specialize for photovoltaic called SCAPS is used in this research to simulate the effect on the solar cells. The solar cell’s structure will be drawn inside the simulation and the parameters for each layers is inserted. The result such as the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), efficiency (η), capacitance-voltage (C-V) and capacitance-frequency (C-f) characteristic will be calculated by the software and all the results will be put into one graph.

Electronic Properties of Polymer-Fullerene Solar Cells

2001 ◽  
Vol 665 ◽  
Author(s):  
V. Dyakonov ◽  
I. Riedel ◽  
C. Deibel ◽  
J. Parisi ◽  
C. J. Brabec ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Fill Factor ◽  
Short Circuit ◽  
Open Circuit ◽  
Light Illumination ◽  
Positive Temperature ◽  
Admittance Spectroscopy ◽  
Spin Resonance

ABSTRACTWe studied the electronic transport properties of conjugated polymer/fullerene based solar cells by means of temperature and illumination intensity dependent current-voltage characteristics, admittance spectroscopy and light-induced electron spin resonance. The short-circuit current density increases with temperature at all light illumination intensities applied, i.e., from 100 mW/cm2 to 0.1 mW/cm2 (white light), whereas a temperature independent behavior was expected. An increase of the open-circuit voltage from 850 mV to 940 mV was observed, when cooling down the device from room temperature to 100 K. The fill factor depends strongly on temperature with a positive temperature coefficient in the whole temperature range. In contrast, the light intensity dependence of the fill factor shows a maximum of 52% at intermediate illumination intensities (3 mW/cm2) and decreases subsequently, when increasing the intensity up to 100 mW/cm2. Further studies by admittance spectroscopy revealed two frequency dependent contributions to the device capacitance. One, as we believe, originates from trapping states located at the interface between composite and metal electrode with an activation energy of EA=180 meV, and the other one is from very shallow bulk states with EA=10 meV. The origin of the latter is possibly the thermally activated conductivity. The photo-generation of charge carriers and their fate in these blends have been studied by light-induced electron spin resonance. We can clearly distinguish between photo-generated electrons and holes in the composites due to different spectroscopic splitting factors (g-factors). Additional information on the environmental axial symmetry of the holes located on the polymer chains as well as on a lower, rhombic, symmetry of the electrons located on the methanofullerene molecules has been obtained. The origin of the signals and parameters of the g-tensor have been confirmed from studies on a hole doped polymer.

Temperature Dependent Transport in Microcrystalline PIN Diodes

2000 ◽  
Vol 609 ◽  
Author(s):  
T. Brammer ◽  
H. Stiebig ◽  
A. Lambertz ◽  
W. Reetz ◽  
H. Wagner
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Extraction Efficiency ◽  
Chemical Vapor ◽  
Open Circuit ◽  
Microcrystalline Silicon ◽  
Temperature Dependent ◽  
Dependent Transport ◽  
Silane Concentration ◽  
Interface Effects

ABSTRACTThe optoelectronic behavior of diodes deposited by plasma enhanced chemical vapor deposition was investigated for a series of different silane concentrations in the gas phase. The purpose of this work was to correlate device characteristics with inherent properties of microcrystalline silicon by experiments and numerical simulations. Dark diode characteristics and, therefore, the open circuit voltage behavior of this series were dominated by the bulk properties of the i-layer (equilibrium carrier concentration) as shown by numerical modeling. Measurement of the solar cell output parameters as a function of the temperature showed that the fill factor of solar cells with small silane concentrations is dominated by the dark diode characteristics. This is in contrast to the temperature dependent fill factor of solar cells with large silane concentration which is limited by the extraction efficiency of the photogenerated carriers. Interface effects dominated the temperature dependent blue response. The gain in blue response increased with temperature and silane concentration by up to 200 % which revealed transport limiting material properties in the vicinity of the p/i-interface. This behavior was attributed to the nucleation region.

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