Physical properties of Bi2 (Te, Se)3 and Bi2Se1.2Te1.8 prepared using solid-state microwave synthesis

Bi-2(Te, Se)(3) and Bi2Se1.2Te1.8 bulk products were synthesised using standard solid-state microwave synthesis. The Bi-2(Te, Se)(3) and Bi2Se1.2Te1.8 were then deposited thermally onto glass substrates at a pressure of 10(-6) Torr. The structure of the samples was analysed using X-ray diffraction (XRD), and the powders and thin films were observed to be polycrystalline and rhombohedral in structure. The surface morphology of the samples was determined using scanning electron microscopy (SEM). From the measurements of optical properties, the energy gap values for the Bi2Te3, Bi2Se3, and Bi2Se1.2Te1.8 thin films were 0.43, 0.73, and 0.65 eV, respectively. (C) 2011 Elsevier B.V. All rights reserved.