Single-crystal SnSe thermoelectric fibers via laser-induced directional crystallization : from 1D fibers to multidimensional fabrics

• Main Authors: Zhang, Jing, Zhang, Ting, Zhang, Hang, Wang, Zhixun, Li, Chen, Wang, Zhe, Li, Kaiwei, Huang, Xingming, Chen, Ming, Chen, Zhe, Tian, Zhiting, Chen, Haisheng, Zhao, Li-Dong, Wei, Lei
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Materials::Functional materials; Flexible Fibers; High Thermoelectric Properties
• Online Access: https://hdl.handle.net/10356/156189
• Institution: Nanyang Technological University

Single-crystal tin selenide (SnSe), a record holder of high-performance thermoelectric materials, enables high-efficient interconversion between heat and electricity for power generation or refrigeration. However, the rigid bulky SnSe cannot satisfy the applications for flexible and wearable devices. Here, a method is demonstrated to achieve ultralong single-crystal SnSe wire with rock-salt structure and high thermoelectric performance with diameters from micro- to nanoscale. This method starts from thermally drawing SnSe into a flexible fiber-like substrate, which is polycrystalline, highly flexible, ultralong, and mechanically stable. Then a CO2 laser is employed to recrystallize the SnSe core to single-crystal over the entire fiber. Both theoretical and experimental studies demonstrate that the single-crystal rock-salt SnSe fibers possess high thermoelectric properties, significantly enhancing the ZT value to 2 at 862 K. This simple and low-cost approach offers a promising path to engage the fiber-shaped single-crystal materials in applications from 1D fiber devices to multidimensional wearable fabrics.