Department of Chemistry, Tsinghua University, 100084 Beijing, People's Republic of China.
J Chem Phys. 2009 Dec 14;131(22):224704. doi: 10.1063/1.3270161.
First-principles band structure calculations coupled with the Boltzmann transport theory are used to study the thermoelectric properties in pentacene and rubrene crystals. In the constant relaxation time and rigid band approximations, the electronic contribution to the Seebeck coefficient is obtained. The absolute value of Seebeck coefficient and its temperature and carrier density dependences are in quantitative agreement with the recent field-effect-modulated measurement. The dimensionless thermoelectric figure of merit is further evaluated based on the calculated transport coefficients and experimental parameters. The peak values of figure of merit in pentacene fall in the range of 0.8-1.1, which are close to those of the best bulk thermoelectric materials. Our investigations show that organic semiconductors can be potentially good thermoelectric materials for near-room-temperature applications.
采用第一性原理能带结构计算结合玻尔兹曼输运理论研究了并五苯和苝晶体的热电性质。在恒定弛豫时间和刚性带近似下，得到了Seebeck 系数的电子贡献。Seebeck 系数的绝对值及其温度和载流子密度依赖性与最近的场效应调制测量结果定量一致。进一步基于计算的输运系数和实验参数评估了无量纲热电优值。并五苯的优值峰值范围为 0.8-1.1，接近最佳体热电材料的值。我们的研究表明，有机半导体在近室温应用中可能是潜在的良好热电材料。
