P-type nitrogen,doped ZnSe grown on n+ -GaAs by molecular beam epitaxy
has been studied by deep-level transient spectroscopy (DLTS) and doub
le correlation DLTS. To achieve p-type doping of ZnSe, we employed an
active nitrogen beam produced by a free-radical plasma source. Four ho
le traps-with activation energies of 0.22, 0.51, 0.63, and 0.70 eV-wer
e detected by DLTS. Two of these-those at 0.51 and 0.63 eV-have never
been observed before in ZnSe. They are probably introduced to the mate
rial by nitrogen doping. The properties of the other two traps-at 0.22
and 0.70 eV-support the hypothesis that both of them are associated w
ith native defects, in agreement with earlier reports. To our knowledg
e this is the first report about direct experimental investigation of
deep states in p-type ZnSe.