Preparation And P-type Doping Of ZnOSe Alloy Thin Films

ZnO is an important wide-bandgap semiconductor. It has many potential applications due to its excellent optoelectronic properties. By incorporating moderate concentration of Se, its bandgap can be reduced by raising the position of the valence band maximum (VBM) and lowering the position of the conduction band minimum (CBM). The elevation of the VBM can make the energy level of some acceptors shallower, thus is beneficial for p-type doping. In this work, ZnOSe alloy thin films with tunable composition and bandgap and N-doped p-type ZnOSe films were synthesized by magnetron sputtering. Na-doped p-type ZnOSe films were synthesized by pulsed laser deposition. The main content of this thesis is illustrated as follows:(1) ZnOSe alloy thin films were synthesized by radio frequency magnetron sputtering on glass. The effect of substrate temperature and O2partial pressure on the composition and band structure of the films were studied. The Se content was reduced and the bandgap increased as the substrate temperature and the O2partial pressure increased.(2) N-doped ZnOSe films were synthesized by magnetron sputtering on quartz. The effect of rapid thermal annealing (RTA) on the structure and properties of the films were studied. After the RTA treatment, the content of Se was reduced and the bandgap increased, the p-type conductivity was realized as well. After annealed at900℃, the film had a hole concentration of1.14×1016cm-3.(3) Na-doped ZnOSe films were synthesized by pulsed laser deposition on quartz. The composition and bandgap of the films can be tuned by adjusting the O2pressure and substrate temperature during the growth process. The p-type conductivity was realized after the RTA treatment. After annealed at900℃, the film had a hole concentration of1.14×1016cm-3.