Synthesis, structure and optical properties of single-crystalline In2O3 nanowires

Highlights: ► Metal and metal oxide one dimensional (1D) nanostructured materials are of crucial importance. ► The paper deals with the synthesis of In2O3 nanowires without the use of catalysts. ► The optical constants and Photoluminescence (PL) of In2O3 nanowires were evaluated. - Abstract: Indium oxide In2O3 nanowires have been recently synthesized revealing interesting properties and used in various applications. In order to reduce as much as possible the influence of undesired dopants and/or impurities on the observed properties, In2O3 nanowires have been grown without the use of catalysts, directly from metallic indium by a vapor transport technique and a controlled oxidation with oxygen–argon mixtures. Depending on the growth conditions (temperature, vapor pressure, oxygen concentration, etc.) different results have been achieved and it has been observed that a 'proper' In condensation on the substrates may enhance the nanowires growth. Detailed structural analysis showed that the In2O3 nanostructures are single crystalline with a cubic crystal structure. The grown In2O3 nanowires were optically characterized in order to evaluate the absorption coefficient, optical band gap, refractive index and extinction coefficient. Room temperature Photoluminescence (PL) spectrum showed broad and intense blue emission at 375 nm.