【作者】 石文； 王冬； 帅志刚；

【Author】 Wen Shi;Dong Wang;Zhigang Shuai;MOE Key Laboratory of Organic OptoElectronics and Molecular Engineering,Department of Chemistry,Tsinghua University;

【机构】 北京市海淀区清华大学化学系有机光电子与分子工程教育部重点实验室；

【摘要】 PEDOT是目前报导的热电性能最好的p型有机热电材料。[1-3]这里,我们利用玻尔兹曼输运方程结合第一性原理能带结构计算,研究了PEDOT单链的热电性能。我们用形变势模型在长波极限下处理电子和纵声学声子的耦合。在拟合形变势常数时,我们使用真空能级校准的方法,并与用内层能级校准方法得到的结果进行比较。我们发现,用真空能级校准方法得到的电子和空穴的形变势常数均比用内层能级校准方法得到的结果要大14~18%。通过计算,我们发现PEDOT单链确实具有较大的赛贝克系数(～0.2 mV K-1),较高的空穴链内迁移率(~700 cm2 V-1 s-1)以及较高的功率因子(~26μW cm-1 K-2)。这些优良的电输运系数表明PEDOT确实是一个优良的热电材料。通过和P3HT单链热电性质的第一性理论计算结果进行比较,我们发现PEDOT具有较小的电子-声子散射矩阵元,从而导致PEDOT具有较P3HT高出3倍的空穴迁移率,进而使得PEDOT具有更加优良的热电性能。更多还原

【Abstract】 We studied the thermoelectric(TE) properties of isolated PEDOT chain. Our methods are based on the Boltzmann transport theory coupled with the first-principles band structure calculations. The electron-phonon couplings are modeled by the deformation potential theory with the vacuum energy level calibration method compared with our previous core energy level calibration method. The first-principles calculations show that the isolated PEDOT chain exhibits large Seebeck coefficient(～0.2 mV K-1), high hole intrachain mobility(～700 cm2 V-1 s-1) and large power factor(～26 μW cm-1 K-2), making it an ideal material for TE applications. We have also compared these results with our previous first-principles investigation on the isolated P3HT chain, and found that smaller electron-phonon scattering matrix elements lead to higher hole mobility of PEDOT than P3HT, which gives rise to better TE performance of the isolated PEDOT chain.更多还原