Electrical characterization of N +-implanted n-type ZnO single crystals: p-n homojunction and deep level defects

Abstract

Unintentionally doped n-type ZnO single crystals were implanted by nitrogen ions with different fluences of 10 13, 10 14 and 10 15 cm -2 respectively. ZnO p-n homojunction was successfully fabricated due to the formation of p-type layer after 650°C post-implantation annealing in air for 30 minutes. Further thermal evolution of deep level defects was studied through thermal annealing up to 1200°C. Electrical characterization techniques including current-voltage (I-V), capacitance-voltage (C-V), Deep Level Transient Spectroscopy (DLTS) and double-correlation DLTS (DDLTS) were used for investigating the control sample, all the as-implanted and annealed samples through Au/n-ZnO Schottky diodes and ZnO p-n junctions. Detailed electrical properties of fabricated devices and characteristics of implantation induced defects were analyzed based on plentiful spectra. Moreover, low-temperature photoluminescence (LTPL) experiments of all the as-implanted and annealed samples were performed and the correlation between results from electrical and optical characterizations was discussed. © 2008 Materials Research Society.