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

¹ College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P.R. China
² Department of Physics, Nanjing University, Nanjing 210093, P.R. China

^a e-mail: bbli@nuaa.edu.cn

Received: 14 January 2012
Revised: 16 March 2012
Accepted: 17 April 2012
Published online: 25 May 2012

Abstract

N-doped Cu₂O thin films have been deposited on glass substrate by reactive magnetron sputtering method under various N₂/O₂ flow ratios from 0 to 1.0. The structural and electronic properties of Cu₂O: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 Cu₂O with the increase of N₂/O₂ flow ratio from 0 to 1.0. However, the crystalline quality of Cu₂O:N films reduced with the increase of the N₂/O₂ flow ratio. The phenomenon of peak shift of Cu₂O(1 1 1) implied that N atoms have been doped into Cu₂O film. The square resistance of Cu₂O:N films linearly decreased from 28.1 to 1.5 (10⁴ Ω/☐) with the increase of N₂/O₂ flow ratio from 0.2 to 0.6 initially, and then it changed slowly with the increase of N₂/O₂ flow ratio from 0.8 to 1.0. Hole density of Cu₂O:N films with various N₂/O₂ 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 Cu₂O:N films was enhanced from 1.2 × 10¹⁶ cm⁻³ to 3.1 × 10¹⁹ cm⁻³ with the increase of N₂/O₂ 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 Cu₂O film.