"Pudding Mold"-type Band as an Origin of Large Thermopower in tau-type Organic Conductors

Abstract

We study the origin of the large thermopower in quasi-two-dimensional a $\tau$-type organic conductor, $\tau -(EDO-S,S-DMEDT-TTF{)}_2(AuB{r}_2{)}_{1+y}$ ($y\le 0.875$), from the view point of a "pudding mold"-type band structure. We calculate the electronic band structure using an \textit{ab initio} band calculation package, and obtain a tight binding model fit to the \textit{ab initio} band structure. Using the model and the Boltzmann's equation approach, we calculate the temperature dependence of the Seebeck coefficient. We conclude that the peculiar band structure is the origin of the large Seebeck coefficient and the appearance of the maximum value at a certain temperature.

proceedings of ISCOM 2009 (to be published in Physica B)

References in corpus (1)

• "Pudding mold" band drives large thermopower in Na${}_x$CoO${}_2$

Cited by in corpus (2)

• Molecular Dependence of the Large Seebeck Effect in τ-type Organic Conductors
• Thermoelectric figure of merit of tau-type conductors of several donors