Quantum efficiency and fatiguing behavior of various luminescence processes in a−As2S3

Measurements of the luminescence excitation spectra of amorphous As₂S₃ show that the quantum effieiencies of the subbandgap luminescence processes decrease whereas that of the band-to-band luminescence increases with increasing excitation photon energy. Furthermore, the band-to-band luminescence shows no fatigue, in contrast to the subbandgap processes. These results allow us to conclude that the usual defects play no role in the band-to-band luminescence process and that surface recombination is not important in the energy range investigated.