| In this work, the performance of ZnO:Al(ZAO) film prepared by mid-frequency pulse magnetron sputtering was studied as follows:Zn metal target with 2wt% Al doped was used in the experiment. The influence of sputtering power, oxygen partial pressure, sputtering pressure and substrate temperature on the performance of ZAO film was studied. Based on the analysis of the experimental result,the optimum technological parameters were found, base vacuum: 4.5×10-4Pa, sputtering power: 180W, sputtering pressure:1.33Pa, substrate temperature: 180℃, oxygen partial pressure: 0.19Pa,target voltage: 320V. Under that experiment condition, the ZAO film with thickness of 600nm was obtained. The resistivity of the film is 5.57×10-4Ωcm, carrier concentration and hallmobility are 2.2×1020cm-3 and 40.1cm2/V·s respectively. The average optical transmittance is over 85% within visible light (400800nm).The textured ZAO film was prepared using two preparation methods which were sputtering-etching and high sputtering power, pressure and substrate temperature sputtering respectively. For sputtering-etching method, the influence of substrate temperature, sputtering pressure and the sputtering power on the surface morphology of the film was mainly studied, the optimum technological parameters were found, base vacuum: 4.5×10-4Pa, sputtering power: 80W;sputtering pressure: 0.3Pa, substrate temperature: 220℃, oxygen partial pressure: 0.043Pa, target voltage: 340V. For high sputtering power, pressure and substrate temperature sputtering method, the influence of pressure on the morphology was studied. The optimum technological parameters are found, sputtering power: 700W, substrate temperature: 250°C, sputtering pressure: 13Pa. The textured ZAO film suited for the thin film solar cell was obtainedusing these two methods. In the a-Si solar cells using textured ZAO films we prepared as the front contact, the short-circuit (Jsc) was increased in evident. In the a-Si solar cells using ZAO films we prepared as the back reflect, the Jsc was increased nearly 1 point. |
