Properties of p-type N-doped Cu2O thin films prepared by reactive sputtering

Abstract

We have investigated the electrical, optical, and structural properties of p-type nitrogen (N)-doped Cu2O thin films prepared at various nitrogen gas flow rates for application in heterojunction solar cells. The N-doped Cu2O thin films were fabricated by facing-target reactive sputtering. The hole concentration of the N-doped Cu2O thin films was affected by N2 gas flow rate. With increasing N2 gas flow rate from 0 to 0.5 sccm, the hole concentration and mobility of N-doped Cu2O films increased sharply. The resistivity, hole concentration, and mobility of the N-doped Cu2O films prepared at a N2 gas flow rate of 4 sccm were 1.9 Ω·cm, 2.0 × 1018 cm−3, and 3.4 cm2·V−1·s−1, respectively. The N-doped Cu2O films showed Cu2O(111) and Cu2O(200) diffraction peaks. Cu2O(200) diffraction peak intensity increased slightly with N2 gas flow rate. The Cu2O(200) peaks were stronger at a N2 gas flow rate of 4 sccm than at other gas flow rates.