溅射功率对钛镓共掺杂氧化锌透明导电薄膜光电性能的影响

Influence of Sputtering Power on the Optical and Electrical Properties of Ti and Ga Codoped ZnO Thin Films

以ZnO∶Ga2O3∶TiO2(97wt%∶1.5wt%∶1.5wt%)陶瓷靶作为溅射源,采用射频磁控溅射技术在玻璃衬底上制备了钛镓共掺杂氧化锌(TGZO)透明导电薄膜,通过X射线衍射仪、四探针仪和分光光度计测试表征,研究了溅射功率对TGZO薄膜晶体结构、电学性质和光学性能的影响。结果表明:所有TGZO薄膜均为六角纤锌矿结构,并且具有(002)择优取向,溅射功率对薄膜性能具有明显的影响。当溅射功率为200 W时,TGZO薄膜的结晶质量最好、电阻率最低、平均可见光透射率最高,品质因数最大(1.22×10-2Ω-1),其光电综合性能最佳。另外,通过光谱拟合方法研究了溅射功率对TGZO薄膜折射率和消光系数的影响,并利用Tauc关系式计算了样品的光学能隙。

Ti and Ga codoped ZnO（TGZO） thin films were deposited on glass substrates by radiofrequency magnetron sputtering technique using a sintered ceramic target of ZnO∶ TiO2∶ Ga2O3（97wt%∶ 1.5wt% ∶ 1.5wt%） as sputtering source.The influence of sputtering power on structural,electrical and optical properties of the TGZO thin films was investigated by X-ray diffraction,four-point probe and UVvisible spectrophotometer.The results show that all the obtained films are polycrystalline with a hexagonal wurtzite structure and grow preferentially in the（002） direction.The sputtering power significantly affects the microstructure and electro-optical characteristics of the deposited films.The TGZO thin film prepared at the sputtering power of 200 W possesses the highest optoelectrical performance,which have the best crystal quality,the lowest resistivity,the highest average visible transmittance and the maximum figure of merit（1.22 × 10-2 Ω-1）.Furthermore,the refractive index and extinction coefficient of the thin films were determined by the method of optical spectrum fitting,and the optical energy gaps were calculated using Tauc＇s relation.