Anisotropic Plastic Deformation Mechanism and Indentation Size Effect During Berkovich Nanoindentation Process of ZnSe Crystals in Micro-nanoscale

Abstract

Zinc selenide (ZnSe), a significant group II–VI semiconductor material, is widely used in a variety of infrared optical thermal imaging and laser systems. Improving the surface quality of ZnSe is an important way to expand its application range. The anisotropy of ZnSe crystals affects the surface quality after material removal. Through the nano-indentation experiment of ZnSe crystals, the anisotropy hardness were observed. The deformation behavior and property differences of materials in different directions has been revealed by molecular dynamics simulation. ZnSe nanofilm plastic deformation is primarily controlled by 1/2 <110 > -type dislocation nucleation and expansion, as per simulation results. The generated dislocation loops during the indentation process exhibit a strong correlation with the applied load. Dislocation slip is generated on all three crystalline planes of the simulation, and the main slip system is {111} <110 >. The (111) crystalline plane has the lowest hardness, and the (100) crystalline plane has the lowest Young’s modulus. The simulation and experimental results show clear anisotropy in hardness, Young’s modulus, elastic modulus, initial plasticity, and elastic recovery rate. Overall, our findings offer a new reference for studying the plasticity of ZnSe crystals.