title: Enhancing the Thermoelectric Figure of Merit by Low-Dimensional Electrical Transport in Phonon-Glass Crystals.
abstract: Low-dimensional electronic and glassy phononic transport are two important ingredients of highly efficient thermoelectric materials, from which two branches of thermoelectric research have emerged. One focuses on controlling electronic transport in the low dimension, while the other focuses on multiscale phonon engineering in the bulk. Recent work has benefited much from combining these two approaches, e.g., phonon engineering in low-dimensional materials. Here we propose to employ the low-dimensional electronic structure in bulk phonon-glass crystals as an alternative way to increase the thermoelectric efficiency. Through first-principles electronic structure calculations and classical molecular dynamics simulations, we show that the π-π-stacking bis(dithienothiophene) molecular crystal is a natural candidate for such an approach. This is determined by the nature of its chemical bonding. Without any optimization of the material parameters, we obtained a maximum room-temperature figure of merit, ZT, of 1.48 at optimal doping, thus validating our idea.
authors.affiliation: †School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Xue-Ya
authors.initials: XY
authors.lastname: Mi
authors.affiliation: ‡Nano Interface Center for Energy (NICE), School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Yu
authors.affiliation: †School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Kai-Lun
authors.initials: KL
authors.lastname: Yao
authors.affiliation: §School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Huang
authors.affiliation: ‡Nano Interface Center for Energy (NICE), School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.|∥State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Nuo
authors.initials: N
authors.lastname: Yang
authors.affiliation: †School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.|⊥Beida Information Research, Tianjin 300457, P. R. China.
authors.forename: Jing-Tao
authors.initials: JT
authors.lastname: Lü
keywords: Thermoelectric effect; electronic structure calculations; molecular crystals; molecular dynamics simulations