溅射功率对镓掺杂氧化锌薄膜光电性能的影响

Effects of the Sputtering Power on the Optoelectronic Property of Ga-doped ZnO Thin Films

本文利用射频磁控溅射的方法首次制备了厚度小于200nm的低电阻率高透过率的镓掺杂ZnO(GZO)薄膜。研究了溅射功率的改变对GZO薄膜光电性能的影响。利用扫描电镜对薄膜的微观结构进行了观察,利用四探针测试仪、紫外-可见分光光度计对GZO薄膜的光电性能进行了测试。实验结果表明:薄膜电阻率随溅射功率增大而迅速下降,从46.6×10-2Ω·cm降低到2.5×10-2Ω·cm,随着溅射功率的增大,薄膜平均透过率在300～350nm范围内有所下降,其吸收宽度增加,但在350～380nm范围内增大,薄膜平均透过率均大于89%,计算显示GZO薄膜的禁带宽度随溅射功率的增加先增大后降低。电子形貌显示薄膜的微观结构由明显的粒子分离结构转变为连续分布状态。

Ga-doped ZnO（GZO） films with low resistivity and high transmittance are got firstly on the condition that the thickness of films is smaller than 200 nm by RF magnetron sputtering.The microstructures of GZO films were observed with Scanning Electron Microscope（SEM）.The optical and electrical properties of GZO films were respectively measured using a four-point probe technique and UV-2102 spectrophotometer.The results show that the resistivity of GZO films which decreased from 46.6×10-2 Ω？cm to 2.5×10-2 Ω？cm decreased rapidly with the sputtering power increasing.When the wavelength range was in 300~350 nm,the increase of sputtering power made the transmittance of GZO films decrease,but the width of transmittance increase.When the wavelength range was in 350~380 nm,the transmittance of GZO films was enhanced.The average transmittance of GZO films are more than 89%.With increasing of sputtering power,the bandgap of GZO films first increases,and then decreases.The surface morphology variation of GZO films show that the morphology of thin film changes from the apparent separation of particles to continuous distribution.