Ghobadi Nader, Zamani Meymian Mohammad-Reza, Fallah Milad
Department of Physics, Faculty of Science, Malayer University, Malayer, Iran.
Department of Solid-State Physics, Faculty of Physics, Iran University of Science & Technology, Tehran, Iran.
Sci Rep. 2024 Apr 2;14(1):7754. doi: 10.1038/s41598-024-58528-3.
This study explores the simultaneous presence of two metal ions of Nickel (Ni) and Copper (Cu) on the formation of a metal selenide (Ni-doped CuSe) in an alkaline environment. The impact of Ni ions on creating the second optical transitions is investigated. Different concentrations amounts of Ni ions (0.01, 0.02, and 0.03 mol) are utilized to produce Ni-doped CuSe semiconductor thin films through a chemical solution deposition method with deposition times varying from 3 to 6 h. Absorbance spectra are employed to determine the band-gap, while Field Emission Scanning Electron Microscopy is utilized for morphological analysis. Structural and elemental analyses are conducted using X-ray Diffraction and Energy Dispersive X-ray Spectroscopy techniques. Additionally, a relatively innovative approach for determining the optical transitions, termed the Derivation Ineffective Thickness Method (DITM), is employed. DITM eliminates the need for thin film thickness and assumptions about the type of transition (direct or indirect) for band-gap calculation. Moreover, a comparison is made between the band-gap obtained from the Tauc model and the transitions obtained by DITM method. Furthermore, it is demonstrated that the optical transitions exhibit two distinct band-gaps associated with nickel selenide (NiSe) as second transition and copper selenide (CuSe) as fundamental transition. The presence of Ni is also found to enhance crystal quality. The study also briefly explores the improved photocatalytic properties of CuSe in the presence of Ni.
本研究探讨了在碱性环境中镍（Ni）和铜（Cu）两种金属离子同时存在时对金属硒化物（Ni掺杂CuSe）形成的影响。研究了Ni离子对产生二次光学跃迁的影响。通过化学溶液沉积法，利用不同浓度的Ni离子（0.01、0.02和0.03 mol）制备Ni掺杂的CuSe半导体薄膜，沉积时间为3至6小时。采用吸收光谱法测定带隙，用场发射扫描电子显微镜进行形态分析。使用X射线衍射和能量色散X射线光谱技术进行结构和元素分析。此外，还采用了一种相对创新的确定光学跃迁的方法，称为导数无效厚度法（DITM）。DITM消除了计算带隙时对薄膜厚度的需求以及对跃迁类型（直接或间接）的假设。此外，还对从Tauc模型获得的带隙与通过DITM方法获得的跃迁进行了比较。此外，结果表明光学跃迁呈现出两个不同的带隙，其中与硒化镍（NiSe）相关的为二次跃迁，与硒化铜（CuSe）相关的为基本跃迁。还发现Ni的存在提高了晶体质量。该研究还简要探讨了在有Ni存在的情况下CuSe光催化性能的改善。
