Synthesis of Homogeneously Alloyed Cu2−x(SySe1−y) Nanowire Bundles with Tunable Compositions and Bandgaps |
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| Authors: | Jun Xu Yong‐Bing Tang Xue Chen Chun‐Yan Luan Wen‐Feng Zhang Juan Antonio Zapien Wen‐Jun Zhang Hoi‐Lun Kwong Xiang‐Min Meng Shuit‐Tong Lee Chun‐Sing Lee |
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| Institution: | 1. Center of Super‐Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (P. R. China);2. Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR (P. R. China);3. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, CAS, Beijing 100101 (P. R. China) |
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| Abstract: | Bundles of homogeneously alloyed Cu2?x(SySe1?y) nanowires with various compositions (0 ≤ y ≤ 1) are controllably prepared via a simple water‐evaporation method under mild conditions. It is found that the nanowire bundles have similar copper contents (0.37 ≤ x ≤ 0.44) and morphologies, and the same face centered cubic (fcc) crystal structure and growth orientation of 110] over the entire composition range of y. To the best of the authors' knowledge, this is the first report on cubic phased ternary Cu2?x(SySe1?y) compounds. It is found that lattice parameter of the Cu2?x(SySe1?y) compound changes linearly with the S content. It is also shown that the direct and the indirect bandgaps of the nanowires vary quadratically with the S content and have bowing parameters of 0.20 and 0.21 eV respectively. Energy‐gap‐tuning via compositional change is achieved for both the direct (1.48?1.87 eV) and the indirect (0.50?0.90 eV) bandgaps. The trends of lattice parameter and bandgap variations are consistent with those described by Végard's Law. |
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| Keywords: | copper chalcogenides nanowires ternary alloy tunable bandgap Vé gard’ s Law |
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