A comparison of fill factor and recombination losses in amorphous silicon solar cells on ZnO and SnO2


Alkaya A., Kaplan R., CANBOLAT H. , Hegedus S.

Renewable Energy, vol.34, no.6, pp.1595-1599, 2009 (Journal Indexed in SCI Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 6
  • Publication Date: 2009
  • Doi Number: 10.1016/j.renene.2008.11.009
  • Title of Journal : Renewable Energy
  • Page Numbers: pp.1595-1599
  • Keywords: Fill factor, Intensity- and frequency-dependence of photocurrent, Quantum efficiency, Recombination, ZnO and SnO2/a-Si:H p-i-n solar cell

Abstract

Effects of ZnO and SnO2 TCO (Transparent Conductive Oxide) substrate materials on hydrogenated amorphous silicon (a-Si:H) p-i-n solar cell performances and recombination kinetics have been investigated. DC and Frequency-resolved photocurrent measurements in a-Si:H p-i-n solar cells of 6 have been carried out experimentally. In particular, the I-V characteristics in the dark and light, the quantum efficiency spectra, the intensity-, bias voltage- and frequency-dependence of photocurrent were obtained. Fill factor (FF) values were determined from I-V characteristics for both types of substrate cells under various illumination levels. The exponent v in the power-law relationship, Iph α Gv, between generating flux density and photocurrent were determined at different bias voltages (DC) and modulation frequencies. High values of Voc (open-circuit voltage), FF, and DC exponent v for the a-Si:H p-i-n solar cell with SnO2 were obtained, but the integrated QE (quantum efficiency), the modulated exponent v were found to be low compared to cells prepared on ZnO substrates. Our results show that these parameters are sensitive to the ZnO and SnO2 substrate materials which act as a window layer allowing most of the incident light to pass into the i-layer of p-i-n cells. © 2008 Elsevier Ltd.