STUDY CHARACTERIZATION OF STRUCTUR AND THERMOELECTRIC PROPERTIES OF SNO2 – BI2TE3

• Main Author: Ridwan Nugraha, Asep
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/58086
• Institution: Institut Teknologi Bandung

The influence of SnO2 in the Bi2Te3 matrix on the structure and thermoelectric properties have been investigated. The XRD and EDS mapping measurement reveals that SnO2 is homogeneously dispersed as a composite on the Bi2Te3 matrix. The thermoelectric properties of Bi2Te3 were found to be affected by the presence of SnO2. The power factor of composite 2% SnO2 - Bi2Te3 increased by 15.4% and achieved a reduction of thermal conductivity by 8.3% at 350 K in comparison to pure Bi2Te3. The remarkable increment of PF is dominated by rising of 10.5% the Seebeck coefficient which depends on the modifcation of potential energy barrier at the interface. While, at high temperature regime, the polaron mechanism was observed under 4% SnO2. The maximum value of activated energy to produce hopping polaron, WH, is 37.6 meV in 2% SnO2, then signifcantly decreased to -34.5meV in 8% SnO2. Furthermore, the reduction of 8.3% thermal conductivity in 2% SnO2 originates from enhanced phonon scattering by SnO2 in the Bi2Te3 matrix. As a result, the largest value of ZT was obtained at 350 K, which is 18.4% higher than the pure Bi2Te3 in the same temperature.