Plastic/Ductile Bulk 2D van der Waals Single‐Crystalline SnSe2 for Flexible Thermoelectrics

• Published in: Advanced science Vol. 9; no. 29; pp. e2203436 - n/a
• Main Authors: Deng, Tingting, Gao, Zhiqiang, Qiu, Pengfei, Wei, Tian‐Ran, Xiao, Jie, Wang, Genshui, Chen, Lidong, Shi, Xun
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.10.2022; John Wiley and Sons Inc; Wiley
• Subjects: Energy; flexible thermoelectrics; plastic/ductile semiconductors; Scanning electron microscopy; Semiconductors; Single crystals; single‐crystalline; SnSe2
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202203436

The recently discovered ductile/plastic inorganic semiconductors pave a new avenue toward flexible thermoelectrics. However, the power factors of current ductile/plastic inorganic semiconductors are usually low (below 5 µW cm−1 K−2) as compared with classic brittle inorganic thermoelectric materials, which greatly limit the electrical output power for flexible thermoelectrics. Here, large plasticity and high power factor in bulk two‐dimensional van der Waals (2D vdW) single‐crystalline SnSe2 are reported. SnSe2 crystals exhibit large plastic strains at room temperature and they can be morphed into various shapes without cracking, which is well captured by the inherent large deformability factor. As a semiconductor, the electrical transport properties of SnSe2 can be readily tuned in a wide range by doping a tiny amount of halogen elements. A high power factor of 10.8 µW cm−1 K−2 at 375 K along the in‐plane direction is achieved in plastic single‐crystalline Br‐doped SnSe2, which is the highest value among the reported flexible inorganic and organic thermoelectric materials. Combining the good plasticity, excellent power factors, as well as low‐cost and nontoxic elements, bulk 2D vdW single‐crystalline SnSe2 shows great promise to achieve high power density for flexible thermoelectrics. Bulk 2D van der Waals (vdW) single‐crystalline SnSe2 is reported as a novel inorganic plastic/ductile thermoelectric (TE) material. It exhibits good deformability and excellent power factor at room temperature. Combining the low cost and nontoxic elements, plastic bulk 2D vdW single‐crystalline SnSe2 is very promising for fabricating the high power density flexible TE device.