In Situ Detection Of Local Structure Transformation Of 2d Snse Nanosheets Through Nanothermomechanical Behavior

2D tin selenide (SnSe) is a promising semiconductive material and its thermal stability is one of the most significant evaluating indicators. However, few works are involved in the temperature-dependent structure stability of 2D SnSe nanosheets. Herein, local structure transformation of a 2D SnSe nanosheet into SnSe2 under high temperature is characterized by a novel atomic force microscope (AFM)-based nanoscale thermomechanical method. Based on an AFM platform, the temperature-dependent nanomechanical properties are investigated. A softness process is found to occur upon the surface of 2D SnSe, accompanying the structure transformation under high temperature. It means that the generation of SnSe2 is due to the structure collapse of SnSe, stemming from the evaporation of Sn atoms under about 90 degrees C. The transformation mechanism is further verified by a real-time nanothermomechanical method. A deeper understanding of the thermal stability and thermal decomposition mechanism of 2D SnSe is promoted. The improved in situ nanomechanical method offers a highly sensitive method to probing the nanomechanical properties of 2D materials.