Different electric-field dependences of geminate and nongeminate recombination in photoluminescence of a-Si:H

In this paper, we present the results of the wideband quadrature frequency-resolved spectroscopy (QFRS) of the electric-field (F) effects on photoluminescence (PL) in a-Si:H: the recombination of geminate electron-hole pairs including excitons is quenched by an electric field, whereas that of nongeminate or distant pairs (DP) is enhanced. The quenching of the geminate recombination at intermediate temperatures is interpreted in terms of the classical Onsager theory. On the other hand, the enhancement of the DP recombination is explained using the effective temperature in diffusion-limited recombination.