S. Tong et al., TEMPERATURE-DEPENDENCE OF VISIBLE PHOTOLUMINESCENCE FROM PECVD NANOCRYSTALLITES EMBEDDED IN AMORPHOUS-SILICON FILMS, Solid state communications, 104(10), 1997, pp. 603-607
The temperature dependence of visible range photoluminescence (PL) pro
perties of nanocrystallites embedded in silicon films deposited at the
substrate temperature T-s= 50-150 degrees C by PECVD method was studi
ed. It was found that there are many differences between them and that
of the near-infrared range PL in ordinary a-Si:H films. Combining wit
h the results of photo-absorption studies of these nanocrystalline sam
ples, we discussed the mechanism of their visible range FL. We suggest
that the light excitation occurs in both the nanocrystallites core an
d their surface regions; however, the radiative recombination can only
occur between the electrons and holes in the localized band tail stat
es of the crystallite surface regions, which are more disordered than
ordinary a-Si:H with their defect states extending more deeply into th
e band gap. (C) 1997 Elsevier Science Ltd.