报告题目：Functional Maps for Exploring Thermoelectric Materials
报告时间：10：00 AM, Apr. 27th(Thursday)
This talk is to discuss our effort in constructing functional maps for the discovery of novel thermoelectric(TE) materials, through a close cooperation between materials simulations and experiments. We tried to build special functional map by looking for the very special point in structure-property relationship, that is, the so-called performance descriptor, for screening novel materials while still pursuing reliable approaches in evaluating transports. The first part is to discuss the so-called pseudocubic approach to rationalize the dependence of maximal electrical power factors (PF) on structural parameters. We construct a PF ~ lattice constant and design a group of diamond-like compounds with high ZT (~1.5) in non-cubic chalcopyrites. The second part of my talk focuses on thermoelectric CoSb3 skutterudites. One of the most interesting features in CoSb3 is the existence of the intrinsic lattice voids which could be partially filled by guest elements. The filling behavior could serve as the performance descriptor. We constructed a filling map for rationalizing the filling behavior of guest fillers as well as the filler’s effect on electrical/thermal transports, leading to the discovery of a series of TE materials with figure of merits ZTs exceeding 1.5. I will also talk about the concept of chemical bond hierarchy, which relates to the discovery of the TE materials with unique part-crystalline part-amorphous state and liquid-like structure, and thus extremely low lattice thermal conductivity. Meanwhile, most of those materials also show good electrical transports due to the existence of conduction network.