溅射气压对直流电源磁控溅射制备掺铝氧化锌薄膜性能的影响

Effect of Sputtering Pressure on the Properties of ZnO Thin Films Prepared by Direct Current Magnetron Sputtering

以ZnO∶Al2O3(2wt%)陶瓷为溅射靶材,采用直流磁控溅射的方法,在普通玻璃衬底上制备ZnO∶Al(AZO)薄膜,研究了溅射气压对AZO薄膜的结构特性、表面形貌及其光电性的影响。XRD和SEM测试表明所有样品均为多晶六角纤锌矿结构,薄膜呈(002)晶面择优生长。用体积百分比为0.5%稀盐酸对制备的AZO薄膜进行腐蚀制绒,腐蚀后其表面形貌随溅射气压的不同而改变。在适当溅射气压下(～1.5m Torr)制备的薄膜,通过溅射后腐蚀工艺,可获得表面形貌具有特征陷光结构的AZO薄膜,其表面呈现"弹坑"状,薄膜的绒度随表面形貌的不同而变化。同时通过优化制备工艺,所有溅射气压下制备的AZO薄膜在可见光及近红外范围的平均透过率大于80%,电阻率低于8.5×10-4Ω·cm,可以满足硅基薄膜太阳电池对透明前电极光电性能的要求。

Al doped ZnO （AZO） thin films were prepared by direct current （DC） magnetron sputtering on general floating glass using ZnO： Al2O3 ceramic as sputtering targets. The effect of sputtering pressure on the microstructure and surface morphology, photoelectric properties of AZO films were investigated According to XRD and SEM test results, all samples obtained were polycrystalline, hexagonal wurtzite structure with oriented in the （002） crystallographic direction. After etched by 0.5% dilute hydrochloric acid, these AZO films showed different surface morphology under various sputtering pressures. AZO thin film surface had a certain light trapping structure with crater-type morphology could be obtained through the processing of etching after sputtered, under appropriate sputtering pressure of - 1.5 mTorr. The hazes of AZO thin films were different with various morphologies. At the same time by optimizing the preparation process, the average transmissions of AZO thin films were more than 80% in the visible and near-infrared range and the resistivities of these films were less than 8.5 ×10^-4 Ω cm, that is suitable for silicon based thin film solar cells as transparent front electrode.