Spin-dependent photoconductivity in undoped a-Si: H

Studies of spin-dependent photoconductivity in a-Si: H are reported. It is shown that, with increasing E.S.R. spin density, the photoconductivity decreases, but its spin dependence increases. The results demonstrate that dangling bonds are important trapping or recombination centres at room temperature. Prolonged exposure to above-gap illumination increases the spin dependence of photoconductivity and provides further evidence that light induces dangling bonds. The spin dependence of photoconductivity is compared with that of luminescence.