3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystals

• DOI: 10.1126/science.aaq1479
• Publication Date: 2018-05-17T18:05:32Z
• Authors: Cheng Chang; Minghui Wu; Dongsheng He; Yanling Pei; Chao-Feng Wu; Xuefeng Wu; Hulei Yu; Fangyuan Zhu; Kedong Wang; Yue Chen; Li Huang; Jing-Feng Li; Jiaqing He; Li-Dong Zhao
• Keywords: Charge carrier; Thermoelectric cooling; Selenide

Thermoelectric technology enables the harvest of waste heat and its direct conversion into electricity. The efficiency is determined by materials figure merit ZT Here we show a maximum ~2.8 ± 0.5 at 773 kelvin in n-type tin selenide (SnSe) crystals out plane. thermal conductivity layered SnSe lowest out-of-plane direction [two-dimensional (2D) phonon transport]. We doped with bromine to make overlapping interlayer charge density (3D transport). A continuous phase transition increases symmetry diverges two converged conduction bands. These factors improve carrier mobility, while preserving large Seebeck coefficient. Our findings can be applied 2D provide new strategy enhance electrical transport properties without degrading properties.