| The aim of this thesis is to develop a novel solution method for the synthesis of gamma phase indium selenide (γ-In2Se3) nanostructures. The effects on the structure and morphology of theγ-In2Se3 nanocrystals are investigated in the ethanol-solvothermal system route via the variation of reaction parameters. A possible growth mechanism of theγ-In2Se3 nanostructures is also proposed based on the characterization and analysis of products obtained in the process. The main contents of this work are summarized as follows:1. Pureγ-In2Se3 is fabricated by the reaction of indium chloride and selenium powders in the 220°C for 20 h in an ethanol-solvothermal system. The purity of the product is largely influenced by the reaction temperature, time and the quantity of reaction sources. When the ratio of InCl3: Se is 1: 1, the product is a mixture ofγ-In2Se3,β-In2Se3 and InSe. While the ratio of InCl3: Se is 1 : 1, we obtainγ-In2Se3 and Se. The pureγ- In2Se3 can be easily attained when the ratio of InCl3: Se is 4: 1. However, with the high ratio of of InCl3: Se, pureγ- In2Se3 is not synthesized if the temperature is lower than 220 oC nor the reaction time is less than 12 h. We also investigate the influence on the morphologies of the product by adding other solvents citric acid, or polyethylene glycol.2.γ-In2Se3 hierarchical flowerlike architectures have been facilely synthesized for the first time via the reaction of indium chloride and selenium powders with the assistance of ascorbic acid at 220°C for 20h in an ethanol-solvothermal system, in which ascorbic acid acts as both reducing and capping agent. SEM, TEM and HRTEM investigations show that these flowerlike In2Se3 architectures with hexagonalγ-phase structure are composed of thin sheet-like nanocrystals. The detailed time-dependent experiments illustrate that flowerlike architectures evolve from solid spheres via an Ostwald ripening process and the effects of the concentration of ascorbic acid and indium precursor on the phase and morphology evolution of In2Se3 flowerlike architectures are intensively studied. Meanwhile, the electrical property of theγ-In2Se3 film is investigated and the conductivity of the film is 2.6×10-6 S cm-1.
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