采用溶胶-凝胶法,在玻璃上制备了不同掺Al浓度的ZnO薄膜。x射线衍射(XRD)结果表明,所制备的薄膜具有c轴择优取向,随着掺Al浓度的增加,(002)峰向低角移动,峰强逐渐减弱。探讨了掺Al对ZnO薄膜发光性能的调控作用,薄膜的透射谱表明:通过改变掺Al浓度,可以提高ZnO薄膜的紫外光透过率,使其吸收边向短波长方向的移动被控制在一定的范围内,从而使薄膜禁带宽度连续可凋;薄膜的光致发光(PL)谱显示:纯ZnO薄膜的PL谱是由紫外激子发光和深能级缺陷发光组成,通过掺Al有助于减少薄膜的缺陷,减弱深能级的缺陷发光,同时紫外带边发射的峰位向高能侧蓝移,与吸收边缘移动的结果相吻合,由紫外发光峰位获得的光禁带与通过透射谱拟合得到的光禁带基本一致。
Pure and AI doped ZnO thin films were fabricated on glass substrates by sol-gel method. An X-ray diffractlon(XRD) was used to analyse the structural properties of the thin films. It is found that all the thin films have a preferential c-axis oreintation. With the increase of AI doping, the peak position of the (002) plane is shifted to the low 20 value. From the spectrometer transmittance data, the band gap energies of AI doped ZnO films were calculated by a linear fitting method. The band gap is found to be large with the increasing dopant concentration. It is found from the photoluminescence(PL) measurement that near band edge (NBE) emission and deep-level (DL) emission are observed in pure ZnO thin films. However,when AI is doped into thin films,the DL emissions of the thin films are depressed. As the concentration of AI increases,the peak of NBE emission has a blueshift to region of higher photon energy,which is coincident with those values calculated by the linear fitting from the transmittance data.