ZnO薄膜紫外光敏特性及晶界势垒的研究

以二水合醋酸锌为原料,采用sol-gel法在石英衬底上制备了ZnO薄膜。用AFM观察表面形貌,通过测量真空条件下不同温度热处理后薄膜的I-V特性,拟合计算晶界势垒高度。研究了热处理温度对ZnO薄膜性能的影响。结果表明:经650℃热处理制备的ZnO薄膜样品具有较佳性能,结构均匀致密,粒径分布为20～32nm。在10V偏压和1.24×10–3W/cm2光强下,紫外光灵敏度为43.95;无光照条件下晶界势垒高度为0.079eV。紫外光照使晶界势垒高度下降为0.011eV,薄膜的紫外光灵敏度与势垒高度的相对变化密切相关。

Study on the UV photo-sensitive characteristic and grain boundary barrier of ZnO thin films

Using Zn(Ac)_2· 2H2O as raw material,ZnO thin films were deposited on quartz substrates by sol-gel method.The surface morphology of the thin films was observed with AFM.The I-V characteristics of ZnO thin films were measured after different heat-treated temperatures in vacuum,then the grain boundary barrier height of the ZnO thin films was deduced.The influences of the heat-treated temperature on the performance of ZnO thin films were investigated.The results show that the properties of ZnO thin films are good heat-treated at 650℃.The ZnO thin films are uniform and dense,and possess an average grain size of 20～30 nm.The UV sensitivity of ZnO thin film is 43.95 measured at bias of 10 V and light intensity of 1.24×10~(-3) W/cm~2.The grain boundary barrier height of the ZnO thin films decrease from 0.079 eV to 0.011eV after UV illumination.The UV sensitivity of the ZnO films is closely related to such change in the grain boundary barrier height.