Enhanced out-of-plane piezoelectric effect in In2Se3/transition metal dichalcogenide heterostructures

The two-dimensional material alpha-In2Se3, which possesses both out-of-plane ferroelectricity and piezoelectricity in monolayer, opens opportunity for the smart material integration in a micro-electro-mechanical system. However, the piezoelectric response decreases with the decreasing thickness of alpha-In2Se3, hindering the application of few-layer alpha-In2Se3 in electromechanical transformation. In this work, we report a strategy to enhance the out-of-plane piezoelectric coefficients by constructing In2Se3/transition metal dichalcogenides (TMDs) heterostructures. Such a strategy shows great piezoelectric enhancement compared with monolayer In2Se3, and the largest e(31) of 2.9x10(-10) C/m is achieved in MoS2/In2Se3. A phenomenological model is further constructed to connect the piezoelectric coefficients with the polarizations of the heterostructures. Furthermore, the induced dipole moment strongly affects the band structure of heterostructures, yielding tunable light absorption. The proposed In2Se3/TMDs heterostructures represent an innovative strategy for the development of future efficient piezoelectric and are attractive for deployment in electromechanical systems.

Automated summary

In this study, a strategy to enhance the out-of-plane piezoelectric coefficients by constructing In2Se3/transition metal dichalcogenides (TMDs) heterostructures was proposed. The strategy showed great piezoelectric enhancement compared with monolayer In2Se3, with the largest e(31) of 2.9x10(-10) C/m achieved in MoS2/In2Se3. A phenomenological model was constructed to connect the piezoelectric coefficients with the polarizations of the heterostructures, and the induced dipole moment strongly affected the band structure of heterostructures, yielding tunable light absorption. The proposed In2Se3/TMDs heterostructures represent an innovative strategy for the development of future efficient piezoelectric materials.