Published online by Cambridge University Press: 21 February 2011
We report a study of the correlation between solar cell parameters and electron transport parameters in a series of a-Si1-xGex:H alloys with bandgaps spanning the range 1.42 – 1.72 eV. Fill factors and open circuit voltages were measured in p-i-n solar cells with 0.32 μm thick i-layers. The electron drift mobility and deep-trapping mobility-lifetime product were measured using transient photocurrent techniques on p-i-n cells with thicker i-layers. The open circuit voltage tracked the bandgap accurately. Both the electron drift mobility and the deep-trapping mobility lifetime product correlated reasonably well with the fill factor measured with illumination absorbed near the p-i interface. We present a discussion of the relationship of the fill factor to these transport parameters.