title: Wurtzite CuInS₂ and CuInxGa₁-xS₂ nanoribbons: synthesis, optical and photoelectrical properties.
abstract: Single crystalline wurtzite ternary and quaternary semiconductor nanoribbons (CuInS(2), CuIn(x)Ga(1-x)S(2)) were synthesized through a solution-based method. The structure and composition of the nanoribbons were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), the corresponding fast Fourier transform (FFT) and nanoscale-resolved elemental mapping. Detailed investigation of the growth mechanism by monitoring the structures and morphologies of the nanoribbons during the growth indicates that Cu(1.75)S nanocrystals are formed first and act as a catalyst for the further growth of the nanoribbons. The high mobility of Cu(+) promotes the generation of Cu(+) vacancies in Cu(1.75)S, which will facilitate the diffusion of Cu, In or Ga species from solution into Cu(1.75)S to reach supersaturated states. The supersaturated species in the Cu(1.75)S catalyst, Cu-In-S and Cu-In-Ga-S species, start to condense and crystallize to form wurtzite CuInS(2) or CuIn(x)Ga(1-x)S(2) phases, firstly resulting in two-sided nanoparticles. Successive crystallizations gradually impel the Cu(1.75)S catalyst head forward and prolong the length of the CuInS(2) or CuIn(x)Ga(1-x)S(2) body, forming heterostructured nanorods and thus nanoribbons. The optical band gaps of CuIn(x)Ga(1-x)S(2) nanoribbons can be continuously adjusted between 1.44 eV and 1.91 eV, depending on the Ga concentration in nanoribbons. The successful preparation of those ternary and quaternary semiconductor nanoribbons provide us an opportunity to study their photovoltaic properties. The primary photoresponsive current measurements demonstrate that wurtzite CuIn(x)Ga(1-x)S(2) nanoribbons are excellent photoactive materials. Furthermore, this facile method could open a new way to synthesize other various nano-structured ternary and quaternary semiconductors, such as CuInSe(2) and CuIn(x)Ga(1-x)Se(2), for applications in solar cells and other fields.
authors: Nanomaterials & Chemistry Key Laboratory, College of Chemistry and Material Engineering, Wenzhou University, Wenzhou 325027, PR China.
authors: Qiang
authors: Q
authors: Li
authors: Lanlan
authors: L
authors: Zhai
authors: Chao
authors: C
authors: Zou
authors: Xusheng
authors: X
authors: Huang
authors: Lijie
authors: L
authors: Zhang
authors: Yun
authors: Y
authors: Yang
authors: Xi'an
authors: X
authors: Chen
authors: Shaoming
authors: S
authors: Huang
mesh_terms: D004553:Electric Conductivity; D011211:Electric Power Supplies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D012666:Semiconductors; D012993:Solar Energy; D013440:Sulfides / Q000737:chemistry* / Q000528:radiation effects; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D046911:Macromolecular Substances; D013440:Sulfides; D017967:Zinc Compounds; C031238:zinc sulfide