Effect of Interface States on the Properties of a-Si:H/c-Si Heterojunction Solar Cells Based on Solar Materials

2012 ◽  
Vol 164 ◽  
pp. 158-161
Author(s):  
Chun Liang Zhong ◽  
L.E. Luo ◽  
Y.Q. Xia
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Interface States ◽  
Open Circuit ◽  
Hole Transport ◽  
Heterojunction Solar Cells ◽  
Interface Recombination Velocity ◽  
Recombination Velocity

The effect of the interface states on the properties of (p+) a-Si:H/(n) c-Si heterojunction solar cells is studied by a set of simulations. The results show that there is almost no effect on the short-circuit current. At very low interface states, there is almost no effect on the open-circuit voltage VOC and the fill factor FF, and then the conversion efficiency. Although, at high interface states, VOC decreases due to the decrease of the excess minority carrier density at the c-Si neutral region and the increase of the effective interface recombination velocity at the heterojucntion interface, which also results in the decrease of FF. In particular, at very high interface states, the hole transport is limited by the interface potential barrier, which results in S-shaped J–V characteristics and low fill factors. As a result, the conversion efficiency decreases with interface states increasing at high interface states.

scholarly journals Role of Vanadium Pentoxide Hole-Extracting Nanolayer in Rubrene/C70-Based Small Molecule Organic Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhen Zhan ◽  
Jing Cao ◽  
Weiguang Xie ◽  
Lintao Hou ◽  
Qin Ye ◽  
...  
Keyword(s):  
Solar Cells ◽  
Vanadium Pentoxide ◽  
Organic Solar Cells ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Hole Transport ◽  
Heterojunction Solar Cells

Vanadium pentoxideV2O5was inserted between the donor layer and the anode as a hole-extracting nanolayer. Compared with devices without a hole-extracting layer, short-circuit current density (JSC), open-circuit voltage (VOC), fill factor (FF), and power conversion efficiency (PCE) of rubrene/C70-based heterojunction solar cells with 3 nm V2O5nanolayer are enhanced by 99%, 73%, 20%, and 310%, respectively. We found that V2O5interlayer can effectively suppress the contact resistance and increase the hole transport capability. The dependence of the device performance on V2O5layer thickness as well as fill factor on exciton dissociation and charge transport was also investigated in detail.

Optical Simulation and Investigation of the Effect of Hysteresis on the Perovskite Solar Cells

NANO ◽  
2019 ◽  
Vol 14 (10) ◽  
pp. 1950127 ◽  
Author(s):  
Farhad Jahantigh ◽  
S. M. Bagher Ghorashi
Keyword(s):  
Grain Size ◽  
Solar Cells ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer

Perovskite solar cells have recently been considered to be an auspicious candidate for the advancement of future photovoltaic research. A power conversion efficiency (PCE) as high as 22% has been reported to be reached, which can be obtained through an inexpensive and high-throughput solution process. Modeling and simulation of these cells can provide deep insights into their fundamental mechanism of performance. In this paper, two different perovskite solar cells are designed by using COMSOL Multiphysics to optimize the thickness of each layer and the overall thickness of the cell. Electric potential, electron and hole concentrations, generation rate, open-circuit voltage, short-circuit current and the output power were calculated. Finally, PCEs of 20.7% and 26.1% were predicted. Afterwards, according to the simulation results, the role of the hole transport layer (HTL) was investigated and the optimum thickness of the perovskite was measured to be 200[Formula: see text]nm for both cells. Therefore, the spin coating settings are selected so that a coating with this thickness for cell 1 is deposited. In order to compare the performance of HTM layer, solar cells with a Spiro-OMeTAD HTM and without the HTM layer in their structure were fabricated. According to the obtained photovoltaic properties, the solar cell made with Spiro-OMeTAD has a more favorable open-circuit voltage ([Formula: see text]), short-circuit current density ([Formula: see text]), fill factor (FF) and PCE compared to the cell without the HTM layer. Also, hysteresis depends strongly on the perovskite grain size, because large average grain size will lead to an increase in the grain’s contact surface area and a decrease in the density of grain boundaries. Finally, according to the results, it was concluded that, in the presence of a hole transport layer, ion transfer was better and ion accumulation was less intense, and therefore, the hysteresis decreases.

Simulation of InAIN/Si Single-Heterojunction Solar Cells Using wxAMPS

2014 ◽  
Vol 665 ◽  
pp. 111-114 ◽  
Author(s):  
Ying Huang ◽  
Xiao Ming Shen ◽  
Xiao Feng Wei
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Indium Content ◽  
Open Circuit ◽  
Heterojunction Solar Cells ◽  
Si Solar Cells

In this paper, InAlN/Si single-heterojunction solar cells have been theoretically simulated based on wxAMPS software. The photovoltaic parameters, such as open circuit voltage, short circuit current, fill factor and conversion efficiency were investigated with changing the indium content and thickness of n-InAlN layer. Simulation results show that the optimum efficiency of InAlN/Si solar cells is 23.1% under AM 1.5G spectral illuminations, with the indium content and thickness of n-InAlN layer are 0.65 and 600nm, respectively. The simulation would contribute to design and fabricate high efficiency InAlN/Si solar cells in experiment.

Nanoscale Phase Separation in Ternary Organic Solar Cells Based on PTB7:PC70BM:IC70BA

2021 ◽  
Vol 21 (11) ◽  
pp. 5749-5755
Author(s):  
Chang Li ◽  
Wei Li ◽  
Xiaoxiang Sun ◽  
Jifei Wang ◽  
Jiayou Tao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Phase Separation ◽  
Active Layer ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Weight Ratio ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Hole Transport ◽  
Fullerene Derivative

As a fullerene derivative, IC70BA is widely used in the ternary organic solar cells (TOSCs) to increase the open circuit voltage (Voc) of the devices. Unfortunately, most of the literature shows that IC70BA will lead to a reduction in the short-circuit current density (Jsc) and fill factor (FF). In this work, IC70BA is added to the PTB7:PC70BM binary system to form the ternary system, which is composed of one donor and two fullerene acceptors. Surprisingly, the addition of IC70BA does not immediately lead to a decrease in Jsc and FF. In fact, the appropriate weight ratio of IC70BA in fullerenes can simultaneously increase the Voc, Jsc, and FF of the TOSCs. The synergistic optimization of the surface and bulk morphology of the ternary active layer suppresses the attenuation of Jsc and FF. The smooth surface and suitable phase separation size effectively guarantee the separation, transport and extraction of the charge. Moreover, the addition of IC70BA can significantly improve the hole transport capacity of the active layer, and the optimal hole mobility is 5.13 – 10”4 cm2V–1S–1. Finally, the TOSCs with 10% weight ratio of IC70BA gives the optimal PCE of 9.24% and ideality factor of 2.3.

scholarly journals Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hyomin Park ◽  
Sung Ju Tark ◽  
Chan Seok Kim ◽  
Sungeun Park ◽  
Young Do Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Solar Simulator ◽  
Heterojunction Solar Cells ◽  
Crystalline Silicon Solar Cells

To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P) gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 μs. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8 mA/cm2, respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.

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.

Fabrication of the Large-Area Integrated a-Si Solar Cells

1986 ◽  
Vol 70 ◽  
Author(s):  
S. Yamazaki ◽  
M. Abe ◽  
S. Nagayama ◽  
K. Shibata ◽  
M. Susukida ◽  
...  
Keyword(s):  
Solar Cells ◽  
Standard Deviation ◽  
Conversion Efficiency ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Process Equipment ◽  
Large Area ◽  
Si Solar Cells

ABSTRACTPIN-structure small-area solar cells using a-Si have been frequently reported on, but only a few reports are available on the study of solar cells using a large-area (10-cm square) substrate, all with a resultant conversion efficiency of above 9.0 %[1,2]. Our study has been concentrated on solar cells using a batch of ten 10-cm square substrates with an average conversion efficiency of 9.5 % or more.As a result, without an anti-reflection coating on the surface of the glass substrate, the following values have been obtained: average conversion efficiency (EFF)=9.63 % (standard deviation of 0.195 %) -Open-circuit voltage (Voc)=12.668 V (standard deviation of 0.215 V) -Short-circuit current (Isc)=78.467 mA (standard deviation of 1.619 mA) -Fill factor (FF)=0.6672 (standard deviation of 0.009)The process, equipment and methods for measurements through which these results were obtained are described below.

scholarly journals Efficiency limits in photovoltaics: Case of single junction solar cells

2014 ◽  
Vol 27 (4) ◽  
pp. 631-638 ◽  
Author(s):  
Marko Jost ◽  
Marko Topic
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
Power Plants ◽  
Short Circuit ◽  
Solar Spectrum ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Standard Test ◽  
Open Circuit ◽  
Limiting Efficiency

The conversion efficiency of solar energy into electrical energy is the most important parameter when discussing solar cells, photovoltaic (PV) modules or PV power plants. So far many papers have been written to address the limiting efficiency of solar cells, the theoretical maximum conversion efficiency an ideal solar cell could achieve. However, most of the researches modelled sun?s spectrum as a blackbody which does not represent a realistic case. In this paper we have calculated the limiting efficiency as a function of absorbers band gap at standard test conditions using the solar spectrum AM1.5. In addition, the other key solar cells performance parameters (open-circuit voltage, short-circuit current density and fill factor) are evaluated while the intrinsic losses in the solar cells are also explained and presented in light of a cell temperature.

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.

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