Physical properties of Bi_2 (Te, Se)_3 and Bi_2Se_(1.2)Te_(1.8) prepared using solid-state microwave synthesis

摘要

Bi_2 (Te, Se)_3 and Bi_2Se_(1.2)Te_(1.8) bulk products were synthesised using standard solid-state microwave synthesis. The Bi_2 (Te, Se)_3 and Bi_2Se_(1.2)Te_(1.8) 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 BJ_2Te_3, Bi_2Se_3, and Bi_2Se_(1.2)Te_(1.8) thin films were 0.43, 0.73, and 0.65 eV, respectively.