Size Dependence of a Temperature-Induced Solid–Solid Phase Transition in Copper(I) Sulfide

• Published in: The journal of physical chemistry letters Vol. 2; no. 19; pp. 2402 - 2406
• Main Authors: Rivest, Jessy B, Fong, Lam-Kiu, Jain, Prashant K, Toney, Michael F, Alivisatos, A. Paul
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.10.2011
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COPPER SULFIDES; DESIGN; FUNCTIONALS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MATERIALS SCIENCE; Nanops and Nanostructures; NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; PHASE DIAGRAMS; phase transition, low high chalcocite, nanoparticle, copper sulfide; SHAPE; SOLAR ENERGY; SULFIDES; TRANSFORMATIONS; TRANSITION TEMPERATURE
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/jz2010144

Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid–solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase transformations suggests the possibility of accessing morphologies that are not found in bulk solids under ambient conditions. These otherwise inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics.