In-Plane Electrostatic Addressable Strain in MoS₂ for Reconfigurable Homojunction Optoelectronics.

Strain engineering offers a powerful route to modulate the electronic structure and light-matter interactions in 2D semiconductors. However, existing approaches largely rely on flexible substrates or mechanically complex micro-electromechanical platforms, which limit scalability, reconfigurability, and on-chip integration. Here we introduce an in-plane isolated gated architecture that establishes strong lateral electrostatic fields across a suspended monolayer MoS₂, delivering large-range, tunable, and reversible in-plane uniaxial strain without any other moving parts, by harnessing the electro-elastic coupling originating from in-plane symmetry breaking. In situ photoluminescence quantifies a monotonic bandgap tuning from 1.83 eV to 1.66 eV under electrostatic field modulation, corresponding to over 3% in-plane strain. With this platform, strain contrast between suspended and supported domains forms an addressable homojunction governed by field magnitude and channel orientation. This strain-defined junction exhibits rectification behavior and a tunable photoconductive cutoff wavelength spanning 640 to 785 nm. Leveraging these properties, a single standalone device achieves wavelength-division multiplexing signal separation and polarization-resolved photodetection without external optical components. These results suggest electrostatic-field-induced strain as a promising, scalable, and CMOS-compatible mechanism for operando localized strain engineering in 2D materials, provides a general route to unlock capabilities in spectral sensing, polarization-aware detection, and compact optical interconnects.