Light-induced Creation of Defects and Lifetime Distribution of Photoluminescence in a-Si:H Based Films

Abstract

ABSTRACTWe have studied the lifetime distributions of photoluminescence (PL) at 10K after the pulsed excitation for a-Si:H based films. Effects of light-induced creation of defects on the lifetime distributions have been studied. The lifetime distributions of PL in a-Si:H based films have a distinct component at about 10 ns together with a longer lifetime component seen in microsecond region. The PL in a-Si:H decreases in intensity after the illumination of visible light. The decreasing of the nanosecond component is slower than that of microsecond component. The decreasing of the PL intensity and increasing of the defect density have also been observed in a-Si:H after illumination of sub-bandgap light, although the absorption coecient is much smaller than that of visible light. The quenching of PL is discussed with distribution of non-radiative lifetime calculated by assuming random distribution of the DBs.