Effect of hydrogen dilution on the open-circuit voltage of hydrogenated amorphous silicon solar cells

The open-circuit voltage (V-oc) of hydrogenated amorphous silicon solar cells has been studied experimentally and by computer simulation. We find that band gap and defect states affect V-oc significantly. Hydrogen (H-2) dilution widens the band gap and reduces density of defect states; both contribute to larger V-oc and better fill factor in H-2 diluted solar cells. Valence band tail narrowing could affect V-oc, but is not included in this study due to lack of available data. (C) 2003 American Institute of Physics.