Tuning the Electronic Structure in the MoS₂/SrTiO₃ Heterojunction via Phase Evolution of the SrTiO₃ Substrate.

Abstract

The coupling between transition metal dichalcogenides (TMDCs) and SrTiO₃ has recently emerged as a fertile platform for discovering interfacial phenomena, where particle interactions, lattice coupling, and dielectric screening give rise to interesting physical effects. These hybrid systems hold significant promise for two-dimensional (2D) electronics, ferroelectric state control, and metastable phase engineering. However, effective modulation of the interfacial electronic structure remains a critical challenge. Here, we investigate the MoS₂/SrTiO₃ heterostructure using scanning tunneling spectroscopy (STS), angle-resolved photoemission spectroscopy (ARPES), and photoemission spectroscopy (PES), complemented by first-principles calculations. We observe a temperature-dependent evolution of the electronic structure and local density of states driven by the structural phase transition of the SrTiO₃ substrate. This modulation proceeds without conventional band reconstruction but leads to direct changes in the bandgap. Our findings may unveil a robust and spatially uniform mechanism for electronic structure control, offering a temperature-triggered degree of freedom for engineering interfacial states in TMDC-based devices.