Ascorbic acid-assisted solvothermal growth of γ-In2Se3 hierarchical flowerlike architectures

Abstract

Gamma phase indium selenide (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 20 h 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 hexagonal γ-phase structures 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 the γ-In₂Se₃ film is investigated and the conductivity of the film is 2.6 × 10⁻⁶ S cm⁻¹. Considering the difficulty in the preparation of indium selenides arising from various phases and versatile stoichiometries, the successful synthesis of pure In₂Se₃ in this work would be of much scientific significance.