Abstract For ZnO, doping transition metal is one of the powerful tools to improve its photoelectric performance. In this study, Mn-doped ZnO thin films with various thickness and different doping concentration were synthesized by low cost sol-gel method. We systematically investigated structural and optical properties of Mn-doped ZnO with different concentrations and film thickness. Research showed that with the increase of Mn doping concentration, the crystallization of ZnO decreased, and the preferred orientation was weakened. Moreover, the ultraviolet–visible (UV–Vis) absorption coefficient rose as the energy gap (Eg) decreases and Urbach energy (EU) increases). In the intrinsic emission region below 380 nm and in the defect emission region of 440–600 nm, Mn-doped 1.5% ZnO showed the strongest emission, then the excessive doping would reduce photoluminescence of ZnO. However, in the defect emissions region of 380–440 nm, pure ZnO showed highest emission that decreased gradually with the increase doping concentration. Meanwhile, as the increase of film thickness, the crystallization properties of ZnO were improved, but there were more cracks which resulted in the decrease of UV–vis absorption coefficient, the decrease of Eg and the increase of EU). Meanwhile, the intrinsic emission enhanced and the defect emissions decreased.

中文翻译：

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溶胶-凝胶法研究Mn掺杂ZnO薄膜的结构和光学性能

摘要 对于ZnO，掺杂过渡金属是提高其光电性能的有力工具之一。本研究采用低成本溶胶-凝胶法合成了不同厚度和不同掺杂浓度的Mn掺杂ZnO薄膜。我们系统地研究了不同浓度和薄膜厚度的 Mn 掺杂 ZnO 的结构和光学性质。研究表明，随着Mn掺杂浓度的增加，ZnO的结晶减少，择优取向减弱。此外，随着能隙 (Eg) 的减小和 Urbach 能量 (EU) 的增加，紫外-可见光 (UV-Vis) 吸收系数增加。在低于 380 nm 的本征发射区和 440-600 nm 的缺陷发射区，Mn 掺杂的 1.5% ZnO 表现出最强的发射，那么过度掺杂会降低ZnO的光致发光。然而，在 380-440 nm 的缺陷发射区域，纯 ZnO 显示出最高的发射，随着掺杂浓度的增加而逐渐降低。同时，随着薄膜厚度的增加，ZnO的结晶性能得到改善，但裂纹增多，导致UV-vis吸收系数降低，Eg降低，EU增加）。同时，本征发射增强，缺陷发射减少。但裂纹较多，导致紫外-可见吸收系数降低，Eg 降低，EU 增加）。同时，本征发射增强，缺陷发射减少。但裂纹较多，导致紫外-可见吸收系数降低，Eg 降低，EU 增加）。同时，本征发射增强，缺陷发射减少。