Non-Radiative Recombination in a-Si:H

ABSTRACTFrequency-resolved photoluminescence spectroscopy (FRS) is used to study non-radiative recombination in a-Si:H using generation rates sufficiently small to garantee geminate recombination at low temperature. The quenching of the photoluminescence by a higher defect density ND and an increase of temperature influences the QFRS spectra differently: Whereas for increasing ND the quenching of the signal is more pronounced on the low frequency side raising temperature leads to a uniform decrease in the entire frequency range. The dependence of the lifetime distribution on ND is quantitatively explained in a model where radiative recombination competes with non-radiative tunneling into defect states.