Flexoelectric polarization synergy enables ultrafast charge transfer for high-efficiency photoconversion in mixed-dimensional MoS2/WSe2 heterostructures

Abstract

Transition metal dichalcogenide nanotubes (NTs) and their heterostructures hold promise for advanced photonics, yet the combined role of flexoelectricity and heterointerface electronegativity mismatch in their performance is unknown. Here, using the atomic-bond-relaxation method, Marcus theory, and the detailed balance principle, we show that in one-dimensional/two-dimensional MoS2-NT/WSe2 heterostructures, the synergistic action of a strain gradient induced flexoelectric field and an interfacial built-in field drives an ultrahigh charge-transfer rate of 8×1013s−1. This mechanism, coupled with the enhanced photoconfinement effect of NT, yields a remarkable photoconversion efficiency exceeding 10%. Our work reveals strain and interface engineering as a powerful strategy for achieving high-performance optoelectronics in low-dimensional systems.