Study of Radiative Recombination Rate of Electron–hole Pairs in Hydrogenated Amorphous Silicon by Means of Frequency Resolved Spectroscopy

Temperature variation of radiative recombination rate of electron–hole pairs in hydrogenated amorphous silicon (a-Si:H) films has been obtained from measurements of photoluminescence (PL) by means of frequency resolved spectroscopy (FRS). The radiative recombination rate increases with increasing temperature. The results are interpreted by considering thermal excitation of the carriers form strongly localized states to shallow tail states. The results also show that the disorder of the amorphous network in the a-Si:H affects the temperature dependence of the radiative recombination rate. Temperature dependence of the radiative recombination rate for the defect PL in a-Si:H films becomes weaker after illumination of intense pulsed light, indicating that the amorphous network becomes more disordered after illumination.