Activation of Nitrogen Acceptor in ZnSe Homo-Epilayer Grown by MOCVD

A ZnSe epitaxial layer doped with nitrogen (N) has been grown on ZnSe substrate at optimized conditions by a low-pressure metalorganic chemical vapor deposition (MOCVD) system using hydrogen as a carrier gas and ammonia as a dopant source. In order to enhance the activation ratio of nitrogen in ZnSe epitaxial layer, ZnSe : N/ZnSe was annealed in atmosphere with zinc-saturated vapor pressure. Photoluminescence spectra measured at 4.2 K from annealed ZnSe : N epilayers showed the stronger I1N emission. C–V measurement showed that the ZnSe : N epitaxial layer is of p-type conductivity and the highest net acceptor concentration reaches as high as 6.7 × 1017 cm—3. This is the highest value for the ZnSe homosystem epitaxial layers grown by the MOCVD method at present. Furthermore, the ionization energy of nitrogen in ZnSe was estimated to be 109 meV by examining the dependence of DAP emission on the measuring temperature.