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采用溶胶-凝胶旋涂法在玻璃衬底上制备了Co,Sn掺杂ZnO系列薄膜.通过金相显微镜和X射线衍射(XRD)研究了Co与Sn掺杂对薄膜的表面形貌和微结构的影响.XRD结果表明,所有ZnO薄膜样品都存在(002)择优取向,特别Sn单掺ZnO薄膜的c轴择优取向最为显著,而且晶粒尺寸最大.XPS测试表明样品中Co和Sn的价态分别为2+和4+,证实Co2+,Sn4+进入了ZnO的晶格.室温光致发光谱(PL)显示在所有的样品中都有较强的蓝光双峰发射和较弱的绿光发射,而在纯ZnO及Co掺杂ZnO薄膜样品中还观察到了较强的紫外发光峰.此外,通过Co,Sn掺杂的控制能够调整薄膜的禁带宽度,进而使得蓝光发光峰发生了位移;同时,掺杂还将影响薄膜中氧位错、锌空位和锌填隙缺陷,因此控制掺杂浓度可以调控薄膜的发光特性.最后,还探讨了不同波段光发射的可能机理.
Co and Sn doped ZnO thin films were prepared on glass substrates by sol-gel spin-coating method.The morphology and micro-morphology of Co and Sn doped films were investigated by metallographic microscope and X-ray diffraction (XRD) XRD results show that (002) preferred orientation exists in all ZnO thin films, especially the c-axis preferred orientation of Sn-doped ZnO thin films is the most significant and the grain size is the largest.XPS tests show that the co- 2 + and 4+, respectively, confirming that Co2 + and Sn4 + enter the crystal lattice of ZnO.The room temperature photoluminescence (PL) shows that there is a strong blue-bimodal emission and a weaker green emission in all the samples , But strong UV emission peaks were also observed in pure ZnO and Co doped ZnO thin films.In addition, the control of Co and Sn doping can adjust the forbidden band width of the films and make the blue luminescence peak shift. At the same time, doping will also affect the oxygen vacancies, zinc vacancies and zinc interstitial defects in the films, so controlling the doping concentration can control the luminescent properties of the films.Finally, the possible mechanism of light emission in different wavelength bands is also discussed.