Effect of gas ratio on p type phosphorus doped ZnO film

Abstract

Phosphorus-doped ZnO (ZnO:P) films were grown on quartz substrate by radiofrequency magnetron sputtering technique using mixture gas of Ar and O₂ with different mass ratios, and then the films were annealed rapidly in air ambient, the properties of ZnO:P film and p-type mechanism were investigated. A stable p type ZnO:P film was obtained by using the mixture gas with mass ratio of Ar to O₂ of 1 to 0·05 at a temperature of 750°C in air ambient, which had a resistivity of 59·75∼59·86 Ωcm, a hole concentration of 2·34 × 10¹⁷∼2·11 × 10¹⁸ cm^− 3 and a mobility of 0·05∼0·47 cm² V^− 1 s^− 1 respectively. The shallow acceptor level was estimated to be located at 113∼125 meV above the valence band. The formation mechanism of p type ZnO:P film was related to the P_Zn–2V_Zn complex acceptors. The p-n homojunction showed typical rectification behaviour.