Revealing the Anisotropic Structural and Electrical Stabilities of 2D SnSe under Harsh Environments: Alkaline Environment and Mechanical Strain

Abstract

As a promising thermoelectric and semiconducting material, the stability of two-dimensional tin selenide (SnSe) under harsh environments is significant for its practical applications. Here, focusing on the key procedures in the device fabrication process, we report the anisotropic structural and electrical stabilities of SnSe under an alkaline environment and mechanical strain. Due to the anisotropic mechanical properties, the SnSe flakes can naturally form long-straight {011} edge planes during the mechanical exfoliation process. Such a cleavage tendency provides an effective crystal orientation identification method to uncover the orientation-dependent properties. We find that the single-crystalline SnSe flakes experience an anisotropic degradation process with the preferable {011} dissolution planes in the alkaline environment and can be gradually transformed to be polycrystalline consisting of SnSe2, Sn, and Se nanocrystals. SnSe flakes present an anisotropic electromechanical response with a gauge factor value that reaches ∼−460 under the uniaxial strain along the ⟨011⟩ directions. Our revealed structural and electrical stability of SnSe under harsh environments can provide guidance for the device design, fabrication, and performance evaluation.

Enhanced Room-Temperature Thermoelectric Performance of 2D-SnSe Alloys via Electric-Current-Assisted Sintering

“…Despite their excellent TE performance, hole-reduced SnSe single crystals have a narrow optimization window and reproducibility. Aside from that, the layered structure of SnSe single crystals poses an obstacle to the mass production and assembly of TE due to weakly confined inter-plane cleavage [ 9 ]. Contrary to the SnSe polycrystals, the rapid and inexpensive synthesis increases their mechanical strength [ 10 , 11 ].…”

Research progress of transition-metal dichalcogenides for the hydrogen evolution reaction

“…Selfassembly from top to bottom is a class of methods that overcome the interlayer interactions in bulk 3D materials to achieve the preparation of 2D materials. [29][30][31][32] Bottom-up is a class of methods used to synthesize 2D materials by guiding chemical reactions through specic methods. [33][34][35] This means that TMDs generally meet the requirements of low cost and earth abundance.…”