Ag/Zn共掺杂TiO_(2)薄膜的制备及其光学性能

Preparation and optical properties of Ag/Zn co-doping TiO_(2)thin films

采用溶胶-凝胶旋涂法制备本征TiO_(2)、Ag单掺Ag-TiO_(2)及Ag/Zn共掺Ag/Zn-TiO_(2)的薄膜样品.测试结果表明:所有TiO_(2)薄膜样品的主要晶面是(101)且没有其他杂质晶面.Ag的掺杂使得样品的晶粒尺寸减小,样品的吸收边出现红移,带隙能减小,最小值为3.476 eV.与本征TiO_(2)和Ag-TiO_(2)相比,随着Zn掺杂原子数分数的增加,样品的(101)衍射峰呈现出先减弱后增强的趋势;样品的半高全宽增加,晶粒尺寸和晶面间距都减小,晶粒得到细化;薄膜的表面形貌得到修饰,变得更为平整、致密且均匀,孔隙和团簇相对较少;吸收边先蓝移后红移,吸光度增加,禁带宽度由3.515 eV减小到3.419 eV.样品中当Zn的掺杂原子数分数为2.00%时,(101)衍射峰最强,峰型最为尖锐,晶粒最小,表面形貌最佳,禁带宽度出现最小值为3.419 eV.

The sol-gel spin coating method was used to prepare TiO_(2),Ag-TiO_(2)and Ag/Zn-TiO_(2)film samples.The test results showed that the main crystal face of all samples was(101)and there was no other impurity crystal face.Ag doping made the crystal size of the sample decrease,the red shift appeared on the absorption edge of the sample,and the band gap energy decreased with a minimum value of 3.476 eV.Compared with intrinsic TiO_(2)and Ag-TiO_(2),with the increasing doping fraction of Zn,the(101)diffraction peak of the sample showed a trend of weakening at first and then strengthening.Besides,the full width of half maximum of the sample increased,the grain size and the crystal planes spacing decreased,and the grains were refined as well;the surface morphology of the film was modified to be more flat,dense and uniform,and the phenomenon of pores and clusters was relatively less.The blue shift appeared on the absorption edge and then the red shift.The absorbance increased and the band gap decreased from 3.515 eV to 3.419 eV.When the doping fraction of Zn was 2.00%,the(101)diffraction peak was strongest and the peak type was sharpest.At this time,the crystal size of the sample was smallest,the surface morphology was optimum,and the minimum band gap was 3.419 eV.