Effect of N doping on hole density of Cu2O:N films prepared by the reactive magnetron sputtering method

Abstract

N-doped Cu 2 O thin films have been deposited on glass substrate by reactive magnetron sputtering method under various N 2 /O 2 flow ratios from 0 to 1.0. The structural and electronic properties of Cu 2 O:N films were investigated by X-ray diffraction (XRD), four-point probe and Hall effect measurements. XRD pattern showed that crystalline structures of all the samples retained single phase of Cu 2 O with the increase of N 2 /O 2 flow ratio from 0 to 1.0. However, the crystalline quality of Cu 2 O:N films reduced with the increase of the N 2 /O 2 flow ratio. The phenomenon of peak shift of Cu 2 O(1 1 1) implied that N atoms have been doped into Cu 2 O film. The square resistance of Cu 2 O:N films linearly decreased from 28.1 to 1.5 (10 4 Ω / ☐) with the increase of N 2 /O 2 flow ratio from 0.2 to 0.6 initially, and then it changed slowly with the increase of N 2 /O 2 flow ratio from 0.8 to 1.0. Hole density of Cu 2 O:N films with various N 2 /O 2 flow ratios from 0 to 0.6 was measured using the Van der Pauw method. All the samples are p -type, and the hole density of Cu 2 O:N films was enhanced from 1.2 × 10 16 cm −3 to 3.1 × 10 19 cm −3 with the increase of N 2 /O 2 flow ratio from 0 to 0.6. The experimental results demonstrated that N doping was an effective method to enhance hole density of p -type Cu 2 O film.