Investigation of Bi2Te2.88Se0.12 bulk single crystal produced using Bridgman method

Abstract

As part of research on the influence of selenium as dopant on bismuth telluride, a successful synthesis of single crystal was carried out. Single crystal of p type conductivity, with the given compound formula, Bi2Te2.88Se0.12, was obtained by the Bridgman process. The obtained empirical formula does not deviate from the given compound formula. Single crystal was characterized by Hall Effect system based on the Van der Pauw method. Also, bulk sample was characterized by Seebeck coefficient (S), thermal conductivity (κ) and electrical resistivity (ρ) measurements, as а function of temperature in the range of 40-320°C by а homemade impedance meter. The prepared single crystal has a figure of merit (Z) of 2.16 x 10-3 K-1 at 40°C. Values of ZT are about 1.0 at 27°C for commercialized p and n type of bismuth telluride ingots. T is absolute temperature.

Keywords

• bulk single crystal
• bridgman method
• hall and van der pauw method
• thermoelectric properties
• doping