Photoluminescence from Si nanocrystals dispersed in phosphosilicate glass thin films: Improvement of photoluminescence efficiency

Photoluminescence (PL) from Si nanocrystals (nc-Si) dispersed in phosphosil icate glass thin films was studied. It was found that, at room temperature, the 1.4 eV PL due to the recombination of electron-hole pairs in nc-Si bec omes intense as the P concentration increases. At low temperatures, an addi tional peak related to defects at interfaces between nc-Si and the matrix w as observed at about 0.9 eV. In contrast to the 1.4 eV peak, the 0.9 eV pea k became weaker with increasing P concentration and almost disappeared at a P concentration of 1.5 mol %. These results suggest that the number of int erface defects decreases with increasing P concentration and that this decr ease leads to an improvement of the band-edge PL of nc-Si. (C) 1999 America n Institute of Physics. [S0003-6951(99)01128-6].