Investigation of sputtering pressure on physical properties of CuO films and the electrical properties-temperature relationship of CuO films and p-CuO/n-GaN heterojunction

CuO had huge application prospects in the fields of semiconductor optoelectronic devices. However, the preparation of high-quality CuO films was still an urgent problem to be solved. Herein, we prepared CuO films at different sputtering pressures (0.6–2.1 Pa) by magnetron sputtering technology. The experiment results showed that the sputtering pressure had an obvious effect on the optical properties, structure, morphology and electrical properties of CuO films. It showed that relatively better CuO films could be prepared at 1.6 Pa. Moreover, Hall effect indicated that the change of ambient temperature had an obvious effect on the resistivity and carrier concentration of CuO films. Correspondingly, the p-CuO/n-GaN heterojunction device was fabricated, and the relationship between carrier transport characteristics and ambient temperature was studied. Ambient temperature had obvious influence on the turn-on voltage and rectification ratio of the device. This work provided a basis for the practical application of CuO-based optoelectronic devices. •The effect of sputtering pressure on the physical properties of CuO film was studied.•The effect of ambient temperature on the electrical properties of CuO films was studied.•Device with high rectification ratio based on p-CuO/n-GaN structure was prepared.•The influence of operating temperature on the carrier transport properties was studied.