Photoconductivity of thin a-Si:H films

Abstract

Photoelectric and optical properties of a-Si:H films with a thickness of 60–100 nm were studied. Temperature dependences of photoconductivity in the temperature range 130–440 K and spectral dependences of the absorption coefficient near the absorption edge were measured. The results of comparative measurements of the room-temperature conductivity and the absorption coefficient in the defect-related subgap spectral range (photon energy hν = 1.2 eV) indicate that the recombination of nonequilibrium carriers and, accordingly, the photoconductivity of a-Si:H films with a thickness of ∼100 nm are determined by the defect concentration in the films.