溶胶-凝胶旋涂法制备In掺杂ZnO薄膜结构和光学性能的研究

Structure and optical properties of IN doped ZnO thin films prepared by sol-gel process and spin-coating

采用溶胶-凝胶(sol-gel)旋涂法在常规玻璃衬底上生长了In掺杂浓度分别为1at%、2at%、3at%、4at%、5at%的ZnO薄膜。借助X射线衍射仪(X RD)、扫描电子显微镜(SEM)、紫外-可见分光光度计(UV-Vis)对样品的晶粒生长、结构以及光学性能进行表征。结果如下:所制备的薄膜均沿(002)方向择优生长,且随着In^3+掺杂浓度增加,衍射峰的峰型及半高宽均呈先降低后升高的趋势;In^3+掺入后,ZnO薄膜晶粒由原来的六边形状发展成类似蠕虫状,同时粒径变小且大小不一;与本征样品相比,掺杂后的ZnO光透过率提高了10%,且吸收边向短波长方向偏移,同时随着In^3+的掺入,薄膜的光学带隙值从3.49 eV增加到3.80 eV。当In^3+掺杂浓度为4at%时,薄膜(002)峰的峰形最为尖锐、峰值最大,晶粒较为均匀、晶格间距更小,光透过率最高,光学带隙值相对较大为3.77 eV。

ZnO thin films with In doping concentr ations of 1at%,2at%,3at%,4at%and 5at%were grown on conventional glass substrates by sol-gel spin coating m e thod.X-ray diffractometer(XRD),scanning electron microscope(SEM)and ultrav i olet-visible spectrophotometer(UV-Vis)were used to characterize the grain gr ow th,structure and optical properties of the samples.The results are as follows:the prepared films all grow preferentially in the(002)direction,and with the increase of In^3+doping concentration,the peak shape and half-height wid th of the diffraction peak show a trend of first decreasing and then increasing;after In^3+doping,ZnO The film grains developed from the original hexagonal sha pe t o a worm-like shape,and the particle size became smaller and different in size;compared with the intrinsic sample,the doped ZnO light transmittance increased by 10%,and the absorption edge The short wavelength direction shifts,and with the incorporation of In^3+,the optical band gap value of the film increases fro m 3.49eV to 3.80eV.When the In^3+doping concentration is 4at%,the peak s hape of the film(002)peak is the sharpest and the peak is the largest,the crystal grains are more uniform,the lattice spacing is smaller,the light transmittance is the highest,and the optical band gap value is relatively large 3.77eV.