Determination of the density of states distribution in the energy gap of a-Si:H

Abstract

The spectral distribution of the density of gap states g(E) in glow-discharge-deposited undoped a-Si:H films has been determined from measurements of the photoconductivity performed in the constant photocurrent mode (CPM) and the thermally stimulated currents (TSC) combined with photocurrents created at the same time by short light pulses of low intensity. For the calculation of the g(E) values the exponent γ, as it results from the photoconductivity measurements, has been taken into account. The calculated g(E) values exhibit a minimum around Ec - E = 0.55 eV.