Exotic Thermoelectric Properties of Coronene-Cyclobutadienoid\nGraphene Nanoribbons

Thermoelectric\nmaterials traditionally incorporate heavy metals\nto achieve low lattice thermal conductivity. However, elements such\nas Te, Bi, and Pb are costly and pose environmental hazards. In this\nstudy, we introduce a novel design strategy for thermoelectric materials,\nfocusing on room-temperature, light-element, and high-ZT materials\nsuch as coronene-cyclobutadienoid graphene nanoribbons (cor<sub>4</sub>GNRs). This material demonstrates a ZT value exceeding 2.1, attributed\nto its exceptionally low phonon thermal conductivity resulting from\nits unique edge structure. Importantly, because its electrical conductance\nand Seebeck coefficient are nearly unaffected by the edge structure,\nthey remain relatively high. This distinct behavior in phonon and\nelectronic transport properties leads to a remarkably high ZT value.\nAdditionally, we discover that applying strain can significantly reduce\nphonon thermal conductivity, potentially increasing the ZT value to\nover 3.0. Our findings provide innovative insights for the design\nand application of advanced thermoelectric materials.