title: Controllable Synthesis of Bandgap-Tunable CuSx Se(1-x) Nanoplate Alloys.
abstract: Composition engineering is an important approach for modulating the physical properties of alloyed semiconductors. In this work, ternary CuS(x)Se(1-x) nanoplates over the entire composition range of 0≤x≤1 have been controllably synthesized by means of a simple aqueous solution method at low temperature (90 °C). Reaction of Cu(2+) cations with polysulfide/-selenide ((S(n)Se(m))(2-)) anions rather than independent S(n)(2-) and Se(m)(2-) anions is responsible for the low-temperature and rapid synthesis of CuS(x)Se(1-x) alloys, and leads to higher S/Se ratios in the alloys than that in reactants owing to different dissociation energies of the Se-Se and the S-S bonds. The lattice parameters 'a' and 'c' of the hexagonal CuS(x)Se(1-x) alloys decrease linearly, whereas the direct bandgaps increase quadratically along with the S content. Direct bandgaps of the alloys can be tuned over a wide range from 1.64 to 2.19 eV. Raman peaks of the S-Se stretching mode are observed, thus further confirming formation of the alloyed CuS(x)Se(1-x) phase.
authors: School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei, 230009, P.R. China. apjunxu@hfut.edu.cn.|Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China. apjunxu@hfut.edu.cn.
authors: Jun
authors: J
authors: Xu
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
authors: Xia
authors: X
authors: Yang
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
authors: Qing-Dan
authors: QD
authors: Yang
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
authors: Xing
authors: X
authors: Huang
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.
authors: Yongbing
authors: Y
authors: Tang
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China.|City University of Hong Kong Shenzhen Research Institute, Shenzhen, P. R. China.
authors: Wenjun
authors: W
authors: Zhang
authors: Department Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, P.R. China. c.s.lee@cityu.edu.hk.|City University of Hong Kong Shenzhen Research Institute, Shenzhen, P. R. China. c.s.lee@cityu.edu.hk.
authors: Chun-Sing
authors: CS
authors: Lee
keywords: chalcogens; copper; nanostructures; selenium; sulfur