Bu Zhonglin, Zhang Xinyue, Shan Bing, Tang Jing, Liu Hongxia, Chen Zhiwei, Lin Siqi, Li Wen, Pei Yanzhong
Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, 4800 Caoan Rd., Shanghai 201804, China.
Sci Adv. 2021 May 7;7(19). doi: 10.1126/sciadv.abf2738. Print 2021 May.
GeTe alloys have recently attracted wide attention as efficient thermoelectrics. In this work, a single-leg thermoelectric device with a conversion efficiency as high as 14% under a temperature gradient of 440 K was fabricated on the basis of GeTe-CuTe-PbSe alloys, which show a peak thermoelectric figure of merit () > 2.5 and an average of 1.8 within working temperatures. The high performance of the material is electronically attributed to the carrier concentration optimization and thermally due to the strengthened phonon scattering, the effects of which all originate from the defects in the alloys. A design of Ag/SnTe/GeTe contact successfully enables both a prevention of chemical diffusion and an interfacial contact resistivity of 8 microhm·cm for the realization of highly efficient devices with a good service stability/durability. Not only the material's high performance but also the device's high efficiency demonstrated the extraordinariness of GeTe alloys for efficient thermoelectric waste-heat recovery.
近年来，锗碲合金作为高效热电材料受到广泛关注。在本工作中，基于锗碲-碲化铜-硒化铅合金制备了一种单腿热电器件，在440K的温度梯度下，其转换效率高达14%，该合金在工作温度范围内呈现出峰值热电优值（）>2.5，平均为1.8。材料的高性能在电子方面归因于载流子浓度优化，在热方面归因于声子散射增强，这两种效应均源于合金中的缺陷。Ag/碲化锡/锗碲接触的设计成功地防止了化学扩散，并实现了8微欧·厘米的界面接触电阻率，从而实现了具有良好服务稳定性/耐久性的高效器件。材料的高性能和器件的高效率都证明了锗碲合金在高效热电废热回收方面的卓越性能。
