Nitrogen doping of ZnSe with trimethylsilylazide, triallylamine or bisditrimethylsilylamidozinc during metalorganic vapour phase epitaxy

Several nitrogen precursors without nitrogen hydrogen bonds were tested to dope ZnSe in a MOVPE process. Bisditrimethylsilylamidozinc (ZnBTM), trimethylsilylazide (TMSiN) and triallylamine (TAN) were used to grow ZnSe:N with ditertiarybutylselenide (DTBSe), diisopropylselenide (DIPSe) and dimethylzinc-triethylamine (DMZn-TEN) at growth temperatures between 340 and 420 degrees C. The samples were analysed by photoluminescence (PL), current-voltage (I-V), capacitance-voltage (C-V) and Hall measurements, The dependence of nitrogen incorporation and electrical activation on growth temperature, VI/II ratio and dopant flow were investigated. In the PL spectra of the layers grown with TMSiN an intense bound-exciton emission, correlated to Zn vacancies is observed, besides the I-1(N) emission line for high dopant flows. The samples grown with ZnBTM and TAN as precursors exhibit a broadening of the excitonic emissions and a shift towards the energetic position of the I-1(N) emission line for increasing nitrogen incorporation in the layers. The intensity of the excitonic emissions in comparison to the donor-acceptor pair emissions remains dominating. Although Hall measurements of several samples doped with ZnBTM and TAN indicate p-type conductivity, the analysis of the C-V and I-V measurements shows the n-type or semi-insulating character of the samples.