Carrierhyphen;collection efficiencies in amorphous hydrogenated silicon Schottkyhyphen;barrier solar cells

摘要

We report the results of a systematic study of correlations in the collection efficiency, collection length, depletion width, midgap density of states and energyhyphen;band gap in sputter and silanehyphen;decompositionhyphen;produced amorphous hydrogenated silicon Schottky diodes. Films produced by sputtering have a collection lengthLc, which is less than the depletion widthW, unlike silanehyphen;decompositionhyphen;produced films for whichLcsime;W. We show that the relatively weak variation of the deduced holehyphen;mobilityhyphen;lifetime product with midgap state density and temperature is consistent with the holes becoming immobilized before recombining. The collection efficiency is found to be controlled dominantly by the fieldhyphen;assisted diffusion of carriers in the depletion region, and not limited by geminate recombination.