Effects of Oxygen Flow Rates on the Physical Characteristics of Magnetron Sputtered Single-Phase Polycrystalline Cu2O Films

Feifan Yang,Jingjie Li,Yibang Fan,Wenbo Peng,Yijian Zhou,Guojiao Xiang,Zhiqiang Zhen,Gaoqiang Deng,Hongyuan Fu,Yang Zhao,Hui Wang

doi:10.1590/1980-5373-mr-2020-0275

Abstract

The single-phase polycrystalline copper oxide (Cu2O) films were prepared on sapphire substrates by radio frequency (RF) magnetron sputtering technology which was characterized by low cost and high efficiency. The influences of oxygen flow rate on physical characteristics of the prepared films were investigated. The XRD results showed that the single-phase Cu2O film exhibited a (110) preferred orientation through the analysis of texture coefficient. The AFM images exhibited that the prepared Cu2O film had the highest surface roughness with a distinctive quadrangular surface morphology. The optical transmittance of the single-phase Cu2O film was under 35% and the band gap energy was calculated to be 2.30 eV, the absorption spectra included the peak wavelength of solar radiation and the high absorptivity made it to be a suitable absorbing material. The Hall measurement indicated that all the samples exhibited p-type conductivity. The resistivity, mobility and carrier concentration of the single-phase Cu2O film was 4625 Ω·cm, 1.87 cm2/v·s and 7.227×1014 cm−3, respectively.

Highlights

Cuprous oxide (Cu2O) is a kind of p-type semiconductor material with cubic structure and direct band gap[1]
The various properties of Cu2O thin films prepared by magnetron sputtering were mainly depended on substrate temperature, oxygen partial pressure, sputtering power and substrate self-bias, etc
Cu2O films were deposited on c-Al2O3 substrates by magnetron sputtering (JGP 300) equipment

Summary

Introduction

Cuprous oxide (Cu2O) is a kind of p-type semiconductor material with cubic structure and direct band gap[1]. Compared with the other inorganic p-type semiconductor materials[2,3,4,5,6], it has been widely used in photo catalysis[7] and humidity sensors[8] due to its characteristics of rich sources, non-toxic, low preparation cost and high optical absorption coefficient[9]. It is an attractive absorber layer for heterojunction solar cells because of a band gap energy of 2.1~2.6 eV10,11. The oxygen partial pressure (oxygen flow rate) could affect the stoichiometric

Methods

Results

Conclusion