Structural Modularization of Cu2Te Leading to High Thermoelectric Performance near the Mott–Ioffe–Regel Limit. Issue 19 (8th April 2022)

• Record Type: Journal Article
• Authors: Zhao, Kunpeng; Zhu, Chenxi; Zhu, Min; Chen, Hongyi; Lei, Jingdan; Ren, Qingyong; Wei, Tian‐Ran; Qiu, Pengfei; Xu, Fangfang; Chen, Lidong; He, Jian; Shi, Xun
• Is Part Of: Advanced materials. Volume 34:Issue 19(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-08
• Subjects: copper telluride -- structural modularization -- the Mott–Ioffe–Regel limit -- thermoelectric; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202108573
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: To date, thermoelectric materials research stays focused on optimizing the material's band edge details and disfavors low mobility. Here, the paradigm is shifted from the band edge to the mobility edge, exploring high thermoelectricity near the border of band conduction and hopping. Through coalloying iodine and sulfur, the plain crystal structure is modularized of liquid‐like thermoelectric material Cu2 Te with mosaic nanograins and the highly size mismatched S/Te sublattice that chemically quenches the Cu sublattice and drives the electronic states from itinerant to localized. A state‐of‐the‐art figure of merit of 1.4 is obtained at 850 K for Cu2 (S0.4 I0.1 Te0.5 ); and remarkably, it is achieved near the Mott–Ioffe–Regel limit unlike mainstream thermoelectric materials that are band conductors. Broadly, pairing structural modularization with the high performance near the Mott–Ioffe–Regel limit paves an important new path towards the rational design of high‐performance thermoelectric materials. Abstract : By structurally‐functionally modularizing Cu2 Te with multiple point defects, mosaic nanograins, and crystal‐amorphicity duality, high thermoelectric performance is obtained near the Mott–Ioffe–Regel limit. This work presents a case of paradigm shift from the band edge to the mobility edge in thermoelectric materials research.