CdSe

1-x

S

x

nanocrystals were grown by annealing silica glass with supersaturate Cd

Se and S at 500～800℃ for 4h

respectively. The absorption and photolumines cence (PL) of the nanocrystals excited with light of different wavelength were measu red at room temperature. The PL spectra were discussed. In the sample annealed at 550℃

no absorption and emission were observed in the range of 300～800nm. This suggested that no CdSe

1-x

S

x

nanocrystals formed. The absorption of 1S

3/2

-1S

e

shifted toward to red with the rising of growth temperatures from 600～800℃ due to the weakening of quantum confinement with the increase of nanocrystal sizes. Mainly broadened peaks named H and L bands

H band corresponding to recombination at the band edge and L band corresponds to radiative recombination as sociated with deep traps

were observed in the grown at 600～650℃. As the growth temperature was raised higher

L bands disappeared gradually and only H bands were observed. This indicated that deep trap density decreased with the increase of growth temperature and the deep traps mainly were surface states. H bands shifted red with the increase of nanocrystal growth tempe ratures. This was due to quantum size effects because nanocrystal mean size increased with the increase of growth temperature. In the nanocrystals grown at 650 ～800℃

a series of obvious small peaks superposed on the broadened bands were also observed. The peak energy for nanocrystals grown at different temperatures was similar and only new peaks were observed in samples grown at lower temperatures. The superposed peaks could be divided into two groups. Within each group

the peaks distributed periodically withenergy separation of 120meV. There was 50me Venergy separation between the two groups. The energy separation was much hig her than that of LO phonon. Size-selective PL spectra of nanocrystals collected using excitation wavelength between 488～650nm indicated that the superposed peak energy did not change with the excited wavelength

only the relative intensity varied with the excitation wavelength.