Simultaneous enhancement of conductivity and Seebeck coefficient in an organic Mott transistor

We report on the electrical conductivity and Seebeck coefficient of an electric-double-layertransistor based on an organic Mottinsulator. The measurements were performed along the two in-plane crystallographic axes (a andc) of the same device. While the Seebeck coefficient along thea-axis was decreased by electron or holedoping, the value along thec-axis was increased by holedoping. This is in contrast to the general trade-off relation between the conductivity and the Seebeck coefficient. The simultaneous enhancement of the conductivity and the Seebeck coefficient is attributed topseudogap formation in the hole-doped state, where a steep slope of thedensity of states emerges at thechemical potential because of the electron interaction.

Source: Applied Physics Letters - December 5, 2016 Category: Physics Authors: Yoshitaka Kawasugi, Kazuhiro Seki, Yusuke Edagawa, Yoshiaki Sato, Jiang Pu, Taishi Takenobu, Seiji Yunoki, Hiroshi M. Yamamoto and Reizo Kato Source Type: research