p-type cuprous oxide thin films with high conductivity deposited by high power impulse magnetron sputtering

CuxO thin films were deposited on glass and silicon substrates by High Power Impulse Magnetron Sputtering (HiPIMS) at room temperature from a metallic copper target. The influence of pulse off-time on the films' structural, morphological and optoelectronic properties was investigated. It was found that the power intensity applied on the Cu target was strongly affected by pulse off-time, which had an important impact on the films' composition. Upon increasing the pulse off-time from 500 μs to 3500 μs (pulse on-time fixed at 50 μs), the films' crystallinity as well as transmittance in the visible region both ameliorate. Meanwhile, the conductivity type changed from n-type to p-type as the films' composition changed. When the pulse off-time was fixed at 2000 μs, the optimal p-type conductivity of about 3 S × cm−1 was achieved, which is the highest p-type conductivity reported for Cu2O films in the last few years. The transition of the films' conductivity type can be utilized for the fabrication of Cu2O-based p-n homojunction, and may also prove useful in developing other oxide films by using HiPIMS technology.