Fabrication and optimization process of p-type Li: ZnO oxide semiconductor

Li-doped ZnO films with various Li contents (0.1-0.8 mol%) were prepared by pulsed DC sputtering system with soft-chemical methods synthesized Li_xZn_{1 - x}O_{1 - x/2} targets. It has been investigated that the structural and electrical properties of deposited films depended on the content of doping in target. We observed p-type conduction with low resistivity for 0.1-0.3 mol% and n-type with decreased resistivity for 0.6-0.8 mol% of Li content on the film. These varieties of electrical resistivity and conductivity are suggested as the role of domination between substitutional acceptor Li_Zn and compensation defects of Li_Zn-Li_i complex along with increasing Li doping amounts on the film, i.e. Li_Zn for p-type and Li_Zn-Li_i for n-type. We also investigate the role of sputtering variables, such as substrate temperature, sputtering power and Ar flow rate, to optimize our sputtering process. Finally, Li_xZn_{1 - x}O_{1 - x/2}p-n homojunction diode is demonstrated to confirm stability of the p-type conduction characteristic in our deposited Li: ZnO film.