Photoluminescence characteristics of NiS nanocrystallites embedded in sol-gel silica xerogel

NiS nanocrystallites embedded in silica xerogel have been prepared using a sol-gel processing. UV-vis spectra, transmission electron micrograph, excitation spectra and photoluminescence (PL) spectra of the samples have all been investigated. The PL spectrum of NiS nanoparticles embedded in sol-gel silica xerogel consists of two emission peaks, one at 440 nm (lambda(ex) = 380 nm) and the other at 610 nm (lambda(ex) = 490 nm). The latter has been assigned to the NiS nanoparticles in sol-gel silica xerogel. (C) 2002 Published by Elsevier Science Ltd.