Electrical Characterization of N~+-implanted n-type ZnO Single Crystals: p-n Homojunction and Deep Level Defects

摘要

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-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.