Strain-tunable interface electrostatics in Janus MoSSe/silk vdW heterostructure for triboelectric nanogeneration

TL;DR

This study explores how strain influences the electrostatics and triboelectric performance of a Janus MoSSe/silk heterostructure, revealing enhanced charge transfer and output in TENGs through interfacial polarization and strain tuning.

Contribution

It provides a first-principles analysis of strain-dependent electrostatics in MoSSe/silk heterostructures, highlighting their potential for high-efficiency triboelectric nanogenerators.

Findings

Tensile strain reduces the band gap more in the heterostructure than in individual materials.

The heterostructure shows a significant work-function shift and increased dipole moment.

Triboelectric output is markedly improved across all strain levels.

Abstract

Understanding and engineering interfacial electrostatics in hybrid two-dimensional (2D) and biomolecular material systems is essential for advancing high-performance triboelectric nanogenerators (TENGs). In this work, we systematically investigate the strain-dependent electronic structure and triboelectric response of Janus MoSSe, silk fibroin, and their van der Waals (vdW) heterostructure using first-principles calculations. Tensile strain induces a pronounced band-gap reduction in the MoSSe/silk interface, exceeding that of the isolated constituents and indicating enhanced interlayer electronic coupling. The vdW heterostructure exhibits a significant work-function shift and a substantially larger dipole moment compared to MoSSe and silk alone, revealing strong interfacial charge redistribution driven by Fermi-level alignment and asymmetric polarization. This enhanced polarization directly amplifies the triboelectric surface charge density, producing values more than double those of pristine MoSSe and several orders of magnitude higher than silk. Consequently, the open-circuit voltage and overall triboelectric output are markedly improved across all strain levels. These results demonstrate that synergistic interfacial polarization and strain engineering can effectively elevate charge separation, storage, and transfer efficiencies, establishing the MoSSe/silk vdW heterostructure as a promising material for next-generation high-efficiency TENGs.