In recent years

interest in ZnSe has increased considerably as a potential candidate for blue light emitting diodes. Cu and Ga are important impurities in crystals of ZnSe.In this paper we study the effect of high Ga concentration on deep center emission in ZnSe:Ga

Cu crystals.Nominally undoped ZnSe boule crystals were grown by sublimation.ZnSe dice with dimension of 3×3×1mm

3

were cut from the boules

and heated in molten alloy of zinc

gallium and copper with different concentration of Ga and Cu(Ga/Zn and Cu/Zn in weight respectively)to introduce the impurities and to obtain their low resistivities. Photoluminescence (PL)spectra in ZnSe crystals were measured using a Model 44W spectrometer with a C31034 pho-tomultiplier. A N

2

pulsed laser of Model QJD-9 was used as the excitation source.Fig.1 shows the PL spectra of ZnSe:Ga

Cu with different Cu concentration when Ga concentration is equal to Cu.It is found that the Cu-G band is prominent in ZnSe crystal with high Cu concentration

while the Cu-R band is prominent in ZnSe crystals with low Cu concentration. This means that the intensity ratio of Cu-G band to Cu-R band increases with increasing Cu concentration

which was reported by Wang et al

[12]

. and Yamaguchi et al

[1

2]

. in ZnSe:Cu crystals.