Doping of As, P and N in laser deposited ZnO films

Abstract

Preparation of p-type ZnO thin films on Al 2O 3 (0 0 0 1) substrates is reported, which involves two different p-type dopant source materials such as Zn 3As 2 and Zn 3P 2 for As and P doping, respectively, during pulsed laser deposition, while an ion implantation method was used to dope N in the ZnO films. The hole concentrations of 2.5×10 17–1.2×10 18 cm −3 have been observed in As-doped p-type ZnO films after being underwent rapid thermal annealing (RTA) at 200 °C under an N 2 ambient. In the case of P doping, 3 mol% P-doped ZnO films at RTA between 600 and 800 °C under an O 2 ambient exhibited p-type behavior with the hole concentrations of 5.1×10 14–1.5×10 17 cm −3. In the case of N doping, after RTA up to 700 °C, films implanted with an N dose of 1×10 12 ions/cm 2 showed p-type conductivity with a hole concentration of ∼6.01×10 17 cm −3 and a low resistivity of ∼5.2×10 −1 Ω cm. The low-temperature photoluminescence results showed the peak associated with the neutral-acceptor bound exciton ( A°, X) emission only in the films showing p-type behavior.