Identification of deep-gap states ina-Si:H by photo- depopulation-induced electron-spin resonance

Abstract

A new technique is described for the microscopic identification of electronic deep levels in semiconductors. Photodepopulation of deep levels is monitored simultaneously with electrical and electron-spin-resonance (ESR) techniques to obtain the distribution of deep levels corresponding to a preselected paramagnetic defect. The technique is demonstrated with combined photodepopulation-induced ESR and photocapacitance measurements on hydrogenated amorphous silicon. The results identify the characteristic Gaussian distribution of midgap states with the distribtuion of the transition between double and single occupancy of the silicon dangling-bond defect.