Ga-Ti共掺杂ZnO透明导电薄膜的微观结构和光电性能研究

Microstructure and Optoelectrical Properties of Ga-Ti Co-doped ZnO Transparent Conductive Thin Films

采用磁控溅射方法在玻璃基片上制备了Ga-Ti共掺杂ZnO(GTZO)透明导电薄膜,通过XRD、四探针仪和分光光度计测试,研究了氩气压强对GTZO薄膜光电性能和晶体结构的影响。结果表明:所有GTZO薄膜均为(002)择优取向的六角纤锌矿结构,其光电性能和晶体结构与氩气压强密切相关。当氩气压强为0.4Pa时,GTZO薄膜具有最大的晶粒尺寸(85.7nm)、最小的压应力(-0.231GPa)、最高的可见光区平均透射率(86.1%)、最低的电阻率(1.56×10-3Ω·cm)和最大的品质因子(4.28×105Ω-1·cm-1),其光电综合性能最佳。另外,采用光学表征方法计算了薄膜的光学能隙和折射率,并利用有效单振子理论对折射率的色散性质进行了分析,获得了GTZO薄膜的色散参数。

Ga-Ti co-doped ZnO （GTZO）thin films were grown on glass substrates by the magnetron sputtering technique.The influence of argon pressure on optical,electrical and microstructural properties of the thin films was investigated by X-ray diffraction （XRD）,four-point probe and spectrophotometer.The XRD patterns indicate that all the thin films have hexagonal wurtzite structure with highly c-axis preferred orientation.The optoelectrical and micro-structural properties of the thin films were observed to be subjected to the argon pressure.The GTZO thin film depo-sited at the argon pressure of 0.4 Pa exhibited the largest crystallite size （85.7 nm）,the minimum compressive stress （-0.231 GPa）,the highest average visible transmittance （86.1%）,the lowest resistivity （1.56＆#215;10 -3 Ω＆#183;cm）and the maximum figure of merit （4.28 ×10 5 Ω-1·cm-1 ）.Furthermore,the optical energy-gap and refractive index of the thin films were determined by optical characterization methods.The dispersion behavior of the refractive index was also studied using the single-effective-oscillator model and the oscillator parameters of the thin films were obtained.