Large-scale synthesis and phase transformation of CuSe, CuInSe2, and CuInSe2/CuInS2 core/shell nanowire bundles.
Facile chemical approaches for the controllable synthesis of CuSe, CuInSe2 nanowire, and CuInSe2/CuInS2 core/shell nanocable bundles were developed. Hexagonal CuSe nanowire bundles with lengths up to hundreds of micrometers, consisting of many aligned nanowires with a diameter of about 10-15 nm, were prepared by reacting cubic Cu(2-x)Se nanowire bundles with a sodium citrate solution at room temperature. The CuSe nanowire bundles were then used as self-sacrificial templates for making bundles of tetragonal chalcopyrite CuInSe2 nanowires by reacting with InCl3 via a solvothermal process. Furthermore, bundles of CuInSe2/CuInS2 core/shell nanocables were obtained by adding sulfur to the reaction system, and the shell thickness of the polycrystalline CuInS2 in the nanocables increased with increasing S/Se molar ratios. It was found that the small radius of copper ions allows their fast outward diffusion from the interior to the surface of nanowires to react with sulfur atoms/anions and indium ions to form a CuInS2 shell. Enhanced optical absorption in the vis-NIR region of CuInSe2/CuInS2 core/shell nanocable bundles is demonstrated, which is considered beneficial for applications in optoelectronic devices and solar energy conversion.
Xu
Jun
J
Center of Super-Diamond and Advanced Films (COSDAF), and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, People's Republic of China.
Lee
Chun-Sing
CS
Tang
Yong-Bing
YB
Chen
Xue
X
Chen
Zhen-Hua
ZH
Zhang
Wen-Jun
WJ
Lee
Shuit-Tong
ST
Zhang
Weixin
W
Yang
Zeheng
Z
D003300:Copper / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053770:Nanowires / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
D018036:Selenium Compounds; C101793:copper indium diselenide; D007204:Indium; C477347:cupric selenide; D003300:Copper; D012643:Selenium