DISTRIBUTION OF LIFETIME OF PHOTOLUMINESCENCE IN BAND-EDGE MODULATED A-SI1-XNX-H FILMS

The recombination process in band-edge modulated (BM) a-Si1-xNx:H has been studied by means of frequency resolved spectroscopy (FRS) and com pared with the results for a-Si:H and a-Si1-xNx:H bulk films. The life time distribution has a component peaked at approximately 1 ms for BM a-Si1-xNx:H and bulk films. Their FRS spectra have been almost indepen dent of generation rate in a-Si1-xNx:H bulk and BM films. Thus the com ponent of 1 ms for a-Si1-xNx:H bulk and BM films is considered to be e mission from triplet excitons. The temperature dependence of lifetime distribution is weak for BM films of shea modulation period, L, and bu lk a-Si1-xNx:H films containing more nitrogen. The results show that t he ground state of the exciton is deep for a-Si1-xNx:H bulk films of l arge x and BM films of shea L.