DISCONTINUOUS CHANGE OF PHOTOLUMINESCENCE LIFETIME WITH TEMPERATURE IN HYDROGENATED AMORPHOUS-SILICON

The radiative lifetime distribution G(tau) in a-Si:H has been evaluate d for monochromatized photoluminescence (PL). Although the PL intensit y in a steady state was almost constant at temperatures lower than 50 K, G(tau) exhibited a drastic change in this temperature range; G(tau) at 13 K was dominated by a single component peaked at 1 ms, whereas a nother component grew up gradually at around 10 mu s with increasing t emperature. In this case, the lifetime changes discontinuously from 1 ms to 10 mu s. Based on G(tau) evaluated for various conditions, PL me chanism in a-Si:H is reconsidered.