2D Self-Assembly of Large-Sized Inorganic Nanosheets Leading to Enhanced Power Factors in Earth-Abundant Cu3SbSe4-Based Flexible Hybrid Films

Yunchen Dou; Lei Yao; Yong Du; Qiufeng Meng; Lei Wang; Di Li

doi:10.1021/acsami.3c18887

2D Self-Assembly of Large-Sized Inorganic Nanosheets Leading to Enhanced Power Factors in Earth-Abundant Cu₃SbSe₄-Based Flexible Hybrid Films

ACS Appl Mater Interfaces. 2024 Mar 20;16(11):14055-14063. doi: 10.1021/acsami.3c18887. Epub 2024 Mar 8.

Authors

Yunchen Dou¹, Lei Yao¹, Yong Du¹, Qiufeng Meng¹, Lei Wang¹, Di Li²

Affiliations

¹ School of Materials Science and Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418, P. R. China.
² Key Laboratory of Materials Physics, Institute of Solid State Physics Chinese Academy of Sciences, Hefei 230031, P. R. China.

PMID: 38457210
DOI: 10.1021/acsami.3c18887

Abstract

Fabrication of large-sized inorganic nanosheets is an efficient strategy to promote carrier transportation in flexible thermoelectric (TE) films. Herein, we report the self-assembly of large-sized Cu₃SbSe₄ nanosheets by using a Se nanowire template via wet chemical synthesis and then vacuum-assisted filter these plate-like microcrystals on nylon to prepare Cu₃SbSe₄ flexible thermoelectric (TE) hybrid films. SEM reveals that the as-synthesized Cu₃SbSe₄ powders by using Se nanowires as selenium sources presented 2D plate-like micron structures uniformly and tightly self-assembled by acute triangle-like nanoparticles. Furthermore, XPS evidences that extra Sb vacancies are generated in the unit cell of Cu₃SbSe₄ crystals synthesized by using the Se NW template, resulting in the shrinkage of the unit cell and the narrowing interplanar spacing, which are characterized by XRD and TEM. As a result, both carrier concentration and carrier mobility have been significantly improved. The high carrier concentration is proved to originate from the extra carriers induced by Sb vacancies, and the high carrier mobility of the film is mainly ascribed to its continuous grain boundaries in the plate-like microcrystal morphology. The large-sized nanosheet Cu₃SbSe₄/nylon hybrid film (CSS MPs) exhibits a high power factor (PF) of 235.45 μW m^-1 K^-2 at 400 K, which is 4.23 times higher than that of the Cu₃SbSe₄/nylon hybrid film (CSS NPs) where Cu₃SbSe₄ crystals are synthesized by using raw Se particles. This work reveals a novel approach to prepare plate-like Se-based semiconductors, which requires both high carrier concentration and high carrier mobility.

Keywords: Cu3SbSe4; film; large-sized nanosheets; power factor; self-assembly; thermoelectric.