Symmetry-driven screening of multifunctional 2D monolayers with valleytronic and piezoelectric properties: a high-throughput study

Abstract

Two-dimensional (2D) materials that combine valley-dependent electronic behaviour with piezoelectric functionality present exciting prospects for multifunctional nanoelectronics and energy-harvesting devices. In this study, we perform a high-throughput screening of the Computational 2D Materials Database (C2DB) to identify non-magnetic 2D semiconductors with minimal atomic complexity (2–3 atoms per unit cell) and high crystal symmetry (space groups P3m1 and Pm2), focusing specifically on materials with band extrema (VBM/CBM) at the K and K′ valleys. A total of 48 monolayers is found to satisfy these criteria. For each candidate, the band structures with spin–orbit coupling (SOC), Berry curvature distributions, and piezoelectric coefficients are computed. The results reveal several monolayers exhibiting strong valley-contrasting properties alongside significant electromechanical responses. Therefore, our research offers a collection of valley-piezotronic materials with great promise for experimental implementation in next-generation devices.