Correlation Between the Raman Crystallinity of p-Type Micro-Crystalline Silicon Layer and Open Circuit Voltage of n-i-p Solar Cells

2015 ◽  
Vol 15 (10) ◽  
pp. 7760-7764
Author(s):  
Junhee Jung ◽  
Sunbo Kim ◽  
Jinjoo Park ◽  
Chonghoon Shin ◽  
Duy Phong Pham ◽  
...  

This article mainly discusses the difference between p-i-n and n-i-p type solar cells. Their structural difference has an effect on cell performance, such as open circuit voltage and fill factor. Although the deposition conditions are the same for both p-i-n and n-i-p cases, the substrate layers for depositing p-type microcrystalline silicon layers differ. In n-i-p cells, the substrate layer is p-type amorphous silicon oxide layer; whereas, in p-i-n cells, the substrate layer is ZnO:Al. The interfacial change leads to a 12% difference in the crystallinity of the p-type microcrystalline silicon layers. When the p-type microcrystalline silicon layer’s crystallinity was not sufficient to activate an internal electric field, the open circuit voltage and fill factor decreased 0.075 V and 7.36%, respectively. We analyzed this problem by comparing the Raman spectra, electrical conductivity, activation energy and solar cell performance. By adjusting the thickness of the p-type microcrystalline silicon layer, we increased the open circuit voltage of the n-i-p cell from 0.835 to 0.91 V.

1998 ◽  
Vol 507 ◽  
Author(s):  
Frank Siebke ◽  
Shigeo Yata ◽  
Yoshihiro Hishikawa ◽  
Makoto Tanaka

ABSTRACTWe investigated p-i-n solar cells with microcrystalline absorber but amorphous contact layers. Fill factor and open circuit voltage depend sensitively on the p/i interface. Using an optimized design of the p/i interface, cells with fill factors up to 65% and open circuit voltages of 0.45 V were deposited on amorphous p-layers. They are comparable to cells on micro- crystalline p-layers. A further increase of the open circuit voltage was achieved by variation of the p/i interface treatment but up to now it was accompanied by a decrease of the fill factor. We attribute this effect to a thin undoped amorphous layer at the p/i interface. Under non-optimized deposition conditions an amorphous instead of a microcrystalline silicon layer is grown at the p/i interface which can be detected by Raman measurements on cell structures. While the proper design of the p/i interface is crucial for the cell performance we did not observe significant differences between cells with amorphous and microcrystalline n-layers. The results reveal that the open circuit voltage is limited by the bulk properties of the undoped microcrystalline silicon.


2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal

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.


2015 ◽  
Vol 212 (4) ◽  
pp. 840-845 ◽  
Author(s):  
Simon Hänni ◽  
Mathieu Boccard ◽  
Grégory Bugnon ◽  
Matthieu Despeisse ◽  
Jan-Willem Schüttauf ◽  
...  

2000 ◽  
Vol 609 ◽  
Author(s):  
T. Brammer ◽  
H. Stiebig ◽  
A. Lambertz ◽  
W. Reetz ◽  
H. Wagner

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.


2016 ◽  
Vol 7 (9) ◽  
pp. 1602333 ◽  
Author(s):  
Qifan Xue ◽  
Yang Bai ◽  
Meiyue Liu ◽  
Ruoxi Xia ◽  
Zhicheng Hu ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Marcel M. Said ◽  
Yadong Zhang ◽  
Raghunath R. Dasari ◽  
Dalaver H. Anjum ◽  
Rahim Munir ◽  
...  

AbstractPoly(3-hexylthiophene) (P3HT) films and P3HT / fullerene photovoltaic cells have been p-doped with very low levels (< 1 wt. %) of molybdenum tris[1-(trifluoromethylcarbonyl)- 2-(trifluoromethyl)-ethane-1,2-dithiolene]. The dopants are inhomogenously distributed within doped P3HT films, both laterally and as a function of depth, and appear to aggregate in some instances. Doping also results in subtle changes in the local and long range order of the P3HT film. These effects likely contribute to the complexity of the observed evolutions in conductivity, mobility and work function with doping levels. They also negatively affect the open-circuit voltage and fill factor of solar cells in unexpected ways, indicating that dopant aggregation and non-uniform distribution can harm device performance.


2013 ◽  
Vol 683 ◽  
pp. 522-525 ◽  
Author(s):  
Zhe Zeng ◽  
Bao Zhang ◽  
Xiu Jun Liu ◽  
Xiao Peng ◽  
Shu Xian Meng ◽  
...  

We have synthesized three novel porphyrin-based sensitizers, in which different substituents were introduced to meso- position. The relationship between meso- substituent and cell performance was investigated. We find porphyrin density could be a key point that affect cell device performance. The highest cell performance was obtained with 4-trans-vinyl- (2'-(5',10',15',20'-tetra (4''-isobutylphenyl) porphyrinato zinc(II))yl) benzoic acid, a short circuit photocurrent density of 10.25 mA cm-2 , an open –circuit voltage of 0.74 V, a fill factor of 68%, and a power conversion efficiency of 5.15% under standard AM 1.5 sunlight.


2014 ◽  
Vol 665 ◽  
pp. 111-114 ◽  
Author(s):  
Ying Huang ◽  
Xiao Ming Shen ◽  
Xiao Feng Wei

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.


2021 ◽  
Vol 5 (3) ◽  
pp. 242-250
Author(s):  
D. Sergeyev ◽  
K. Shunkeyev ◽  
B. Kuatov ◽  
N. Zhanturina

In this paper, the features of the characteristics of model thin-film solar cells based on the non-toxic multicomponent compound CuZn2AlS4 (CZAS) are considered. The main parameters (open-circuit voltage, short-circuit current, fill factor, efficiency) and characteristics (quantum efficiency, current-voltage characteristic) of thin-film solar cells based on CZAS have been determined. The minimum optimal thickness of the CZAS absorber is found (1-1.25 microns). Deterioration of the performance of solar cells with an increase in operating temperature (280-400 K) is shown. It is revealed that in the wavelength range of 390-500 nm CZAS has a high external quantum efficiency, which allows its use in designs of multi-junction solar cells designed to absorb solar radiation in the specified range. It is shown that the combination of CZAS films with a buffer layer of non-toxic ZnS increases the performance of solar cells.


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