Photo-Induced Excess Conductivity in Doping Modulated Amorphous Semiconductors

Abstract

AbstractThe metastable excess conductivity σ(E) observed in hydrogenated amorphous silicon (a-Si:H), that is alternately doped n- and p- type, is compared with the Staebler-Wronski effect and other metastable conductivity changes observed in compensated a-Si:H and in oxidized p- type a-Si:H respectively. We find that Dohler's model of electron-hole pair separation in the pn-junction fields cannot account for the long life of a(E) near and above 300ºK. A defect complex associated with boron having a large configurational relaxation after releasing an electron by photoexcitation is considered as an explanation for σ(E).