沉积功率对溅射制备镓镁共掺杂氧化锌薄膜光学和电学性能的影响

Influence of deposition power on the optical and electrical performance of sputtered gallium-magnesium co-doped zinc oxide thin films

采用控溅射工艺制备了镓镁掺杂氧化锌(Zn O:Ga-Mg)透明导电薄膜,通过多种表征技术研究了沉积功率对薄膜结构、形貌、光学和电学性能的影响.实验结果表明,所有薄膜均为六角纤锌矿结构并且具有c轴择优取向生长特点,并且沉积功率明显影响薄膜的性能.沉积功率为150 W时所制备的Zn O:Ga-Mg薄膜具有最好的结晶质量和光电性能,对应的平均可见光透过率为92.2%、电阻率为1.18×10^(-3)Ω·cm、品质因数为1.04×10^(4)Ω^(-1)·cm^(-1)、晶格应变为1.95×10^(-3)、位错密度为1.17×10^(15)m^(-2).另外,利用光学表征方法获得了Zn O:Ga-Mg薄膜的光学常数,同时根据单振子WDD模型研究了薄膜的光学色散性质,得到了薄膜的振子参数、非线性光学常数和光学能隙.研究结果表明沉积功率是影响Zn O:Ga-Mg薄膜结构和光电性能的最重要的工艺参数之一.

The transparent conductor thin films of gallium-magnesium co-doped zinc oxide(ZnO:Ga-Mg)were deposited by magnetron-sputtering process.The deposition power dependence of structural,morphological,optical and electrical properties of the thin film was characterized by various techniques.The experimental results indicate that all the thin films have hexagonal wurtzite structure with highly c-axis preferred orientation along the(002)plane,and the deposition power strongly affects the properties of ZnO:Ga-Mg thin films.The thin film prepared at the deposition power of 150 W exhibits the best crystallinity quality and photoelectric properties,with the highest average visible transmittance of 92.2%,the lowest resistivity of 1.18×10^(-3)Ω∙cm,the maximum figure of merit of 1.04×10^(4)Ω-1∙cm-1,and the minimum lattice strain of 1.95×10^(-3)and dislocation density of 1.17×10^(15)m^(-2).The optical constants of the thin films were obtained by the optical characterization methods.The optical dispersion behavior of the thin films was studied in terms of the single-oscillator Wemple-DiDomenico(WDD)model,and the oscillator parameters,non-linear optical constants and optical energy-gaps were achieved.The results demonstrate that the deposition power is one of the most important processing parameters to affect the structure,optical and electrical properties of ZnO:Ga-Mg thin films.