Spin-dependent effects in porous silicon

Abstract

Luminescent anodically etched porous silicon is studied with electron spin resonance, optically detected magnetic resonance, and spin-dependent photoconductivity. The Pb center, the silicon dangling bond at the crystalline Si/SiO2 interface, is found to be the dominant paramagnetic defect, influencing both photoconductivity and photoluminescence. The assignment is supported by the observation of the corresponding 29Si hyperfine lines. A second hyperfine split pair is attributed to Si-F complexes formed during the etching process and remaining in the porous material.