Quantum efficiency of light-induced defect creation in hydrogenated amorphous silicon and amorphous As₂Se₃

Abstract

The quantum efficiency (QE) of light-induced metastable defect creation in hydrogenated amorphous silicon (a-Si : H) and amorphous As₂Se₃ (a-As₂Se₃) by bandgap and subgap illumination has been deduced from photocurrent measurements. The QE decreases with increasing number of absorbed photons. A higher QE for a-As₂Se₃ than for a-Si : H has been observed and this is interpreted in terms of the higher structural flexibility of a-As₂Se₃. We have also found that, for both materials, subgap illumination yields a higher QE than does bandgap illumination.

Acknowledgement

Part of this work has been supported by a grant-in-aid for scientific research (C) from the Ministry of Education in Japan.