Structural and microstructural characterization of Bi2Te3 films deposited by the close space vapor transport method using scanning electron microscopy and X-ray diffraction techniques

► Close space vapor transport (CSVT) is used to deposit Bi2Te3. ► Temperature range 325-350 °C is appropriate for obtained Bi2Te3 by CSVT. ► At CSVT substrate temperatures higher than 400 °C other Bi-Te phases appear. ► Phases different from Bi2Te3 degrade the thermoelectric properties. ► Non-stoichiometry and stacking sequence is the structural key of Bi-Te system.