Title :
Effect of a wide band gap emitter layer and its patterning on the performance of a-Si:H based heterojunction solar cells
Author :
Chatterjee, Parsathi
Author_Institution :
Energy Res. Unit, Indian Assoc. for the Cultivation of Sci., Calcutta, India
Abstract :
Simulation of carrier transport in heterojunction p-i-n structure solar cells has been used to study the effect of a wide band gap p-layer and its contact barrier height (φbo) on cell performance. We find recombination loss at the front contact is small when the emitter layer has a wider band gap. Thus the short circuit current in these structures is and practically independent of φbo. However, if φbo is held constant, the effect of increasing the p-layer band gap is actually to depress the open circuit voltage (Voc). The performance of heterojunction cells deposited on ITO can then only be explained by assuming a larger φ bo. A novel patterning of the p-a-Si-C:H layer has been explored and found to increase Voc by 0.1 volts and the efficiency by over 10%
Keywords :
amorphous semiconductors; electron-hole recombination; elemental semiconductors; energy gap; hydrogen; minority carriers; p-n heterojunctions; semiconductor device models; short-circuit currents; silicon; solar cells; ITO; Si:H; a-Si:H heterojunction solar cells; carrier transport simulation; contact barrier height; front contact; heterojunction p-i-n structure solar cells; open circuit voltage depression; p-a-Si-C:H layer; p-layer patterning; recombination loss; short circuit current; solar cell performance; wide band gap emitter layer; Electrons; Heterojunctions; Optical losses; PIN photodiodes; Photonic band gap; Photovoltaic cells; Poisson equations; Short circuit currents; Voltage; Wideband;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.520031
