Al element is inportant donor impurity in ZnSe

which substitutes Zn site as a single donor with the level close to the conduction band.Meanwhile

Al

Zn

may also combine with V

Zn

to foim self-activated center(V

Zn

-Al

Zn

).Many authors have discussed the luminescence properties of Al-doped ZnSe at high temperature and veiy few have discussed it at lower temperature.In order to study behavior of Al inpurity in ZnSe

Al was doped into high-purity ZnSe single crystal by thermo-dirfusion technique under Zn saturation vapour pressure in the range oi 300℃-900℃.The photoluminescence spectra at liquid ni-quid nitrogen temperature show that very strong blue emission peaks in band edge and a broad emission band B located at 2.0eV were observed for undoped ZnSe;another band A

besides band B

was found at 2.3eV in Al-doped ZnSe.When the diffusion temperature is below 600℃

the emission intensities of Band A and B increase when the diffusion temperature increases and moreover

increasing rate of the emission in intensity for band B is more rapid than that of band A.Emission intensities of band A and B dropped down suddenly when the diffusion temperature over 600℃ For higher diffusion tempera-ture

their intensities increase again the increase of band B is slower than band A.