Growth and characterization of α-In2Se3 single crystals grown by using the chemical transport reaction technique

Single crystals of α-In2Se3 were grown by using the chemical transport reaction technique with iodine as a transporting agent. The grown single crystals had a bulk plate-like structure with a thickness of 150 μm and a large surface area of 8 × 6 mm. The chemical electron probe microanalysis showed In = 40.69 at% and Se = 59.31 at%, a stoichiometric composition of In2Se3. X-ray diffraction studies indicated that the compound was a single crystal with an α-phase. Optical absorption measurements at 298 K gave an optical energy gap of 1.42 eV for a direct transition.