Point defect study of hemispheric p-n-p micro structures in CuInSe2 single crystals

Microstructures in p-CuInSe₂ single crystals tailored by the strong electric field has been studied using the methods of local cathodoluminescence, EBIC, C-V characteristics and DLTS spectra, and has been considered through a prism of elemental stability in the ternary compound. The analysis of the spectra has allowed us to attribute experimental features to optical transitions associated with donor and acceptor levels of V_Cu, V_Se, Cu_i point defects. The capacitance study by the C-V characteristics and DLTS spectra as well as the EBIC test have shown formation of diode-type or transistor-type microstructures. The | N _D -N ₄ I concentration profile, thermal activation and emission energies of 22–25 meV and 170 meV, and a capture cross-section σ_h=2×l0^-19 cm² of the deep donor level have been obtained for the microstructures. The two-stage resistive model has been considered for the p-n and p-n-p junction formation.