P-TYPE CONDUCTION OF ZNSE HIGHLY DOPED WITH NITROGEN BY METALORGANIC MOLECULAR-BEAM EPITAXY

Highly conductive p-type ZnSe layers have been grown reproducibly as a consequence of high nitrogen-doping (≈1019cm-3) by using metalorganic molecular beam epitaxy (MOMBE). The dependence of electrical and photoluminescent properties on substrate temperature (Ts) has been investigated. p-Type conductivity of the ZnSe films at room temperature is enhanced with an increase in Ts; e.g. from a high 0.1 MΩcm resistivity at Ts=300°C to a low 0.57 Ωcm resistivity at 450 °C. By contrast, the dependence of the electrical properties for undoped ZnSe on Ts is similar to that of nitrogen-doped ZnSe except for the type of conductivity. The n-type resistivity of undoped ZnSe also decreases with an increase in Ts (e.g. 20 KΩcm at 300°C to 3.5 Ωcm at 400°C). A nitrogen-doped p-type ZnSe/undoped n-type ZnSe junction grown at 350°C on n-GaAs (100) has been succesfully produced. The diffusion potential of the p-n junction can be evaluated to be between 2.45 and 2.55 eV from the C-2-V plot. Observations of electron beam induced current (EBIC) have also shown formation of the p-n junction. At 77 K bluish emission has been observed from the p-n junction with a 5V forward-bias voltage. © 1989.