Advanced Topics on Condensed Matter Physics
Department of Physics, NCU
A Comparison of Thermoelectric Properties for Simulation Results and Experiment Data of Bulk Silicon
Speaker
Dr. Ken-Ming Lin (postdoctoral fellow)
Computational Materials and Nanoscale Transport Groups
Department of Physics, National Central University
Date 2016/12/15 (Thur)
Time 14:00
Place S4-625
Abstract: The purpose of this study was to compare theoretical calculations and experiment data for Seebeck coefficients (S) of p- and n- doped bulk silicon. Two ingredients are used in our approach: first-principle density functional theory calculation using the local density approximation with a correction of a quasiparticle band gap and a temperature (T) dependent scissor operator, Eg(T) = 1.17 – (4.73 x 10-4 T2 ) / (T + 636) eV due to electron-phonon interaction [1], as implemented in the VASP code [2], and the Boltzmann equation in the relaxation time approximation without band index n and crystal momentum k dependence [3], as implemented in the BoltzTrap code [4]. We found that the calculated Seebeck coefficient times temperature (SxT) of lightly doped pand n-silicon is similar to experiment data in the low temperature range but has a significant difference in the high temperature. In contrast, the calculated Seebeck coefficient of mediumand high-doped p- and n-silicon are similar to the experiment data at high temperature but has a deviation at low temperature [5]. The reasons for this erratic pattern could be due to the constant relaxation time approximation.