Preparation of Bi2Te3 films by hot-wall epitaxy and characterization of p-n junction

The deposition of bismuth telluride thin films, as well as of Bi-Sb-Te and Bi-Te-Se ternary alloys by hot-wall epitaxy, has been optimized on various substrates like Si, SiO2 and SiO2/Si. In order to enhance the thermoelectri c power, we investigated the electrical conductivity sigma, the Hall coeffi cient RH and the Seebeck coefficient S. The properties of the epitaxial fil ms grown on SiO2 and on SiO2/Si substrates are rather similar whereas for B i-2 (Te1-xSex)(3) ternary alloys, the n and p doping is close to the optimu m value that can be from bona fide expected. Finally, the study of current- voltage characteristics at room temperature, for a p-Bi2Te3-n-Bi:Te-3 Junct ion allowed us to determine various and important parameters (n, R-s, J(s) and Phi (B)).