Compensation processes in molecular beam epitaxially grown zinc selenide doped with nitrogen

Recent work has shown that nitrogen produced in a plasma source is a p-type dopant in MBE grown ZnSe with N_a - N_d to 1×10¹⁸ cm^-3, but at these concentrations the material is highly compensated. In a previous study, we have examined the PL spectra of nitrogen doped material grown in our laboratory and have shown that there are two sets of donor-acceptor pair (DAP) peaks which can be explained by a simple model involving a nitrogen acceptor and two donors. The first donor is a native shallow donor and the second is a nitrogen related compensating donor thought to be a complex of the form V_Se-Zn-N_Se. Optically detected magnetic resonance results on samples showing both shallow and deep DAP luminescence show signals due to the shallow isotropic donors and deep anisotropic donors consistent with our proposed model. Calculations of the vacancy concentrations and degree of compensation that should be expected in nitrogen doped ZnSe show that at all temperatures and under all growth conditions the material is highly undersaturated with vacancies. The barriers operating to prevent the compensation are discussed. © 1994.