In the fields of modern information technology and optoelectronics, the exploration of new physical effects and their applications has become a key driving force for scientific and technological progress. As Moore’s law approaches its physical limits, it is particularly important to explore new materials and technologies that overcome the limitations of traditional semiconductor materials. Excitons, which are electrically neutral, hydrogen-like boson quasi-particles, are expected to combine the advantages of electrons and photons, thereby enhancing optoelectronic system interconnectivity. This makes them highly promising for next-generation optoelectronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDs) semiconductors, owing to quantum confinement and reduced dielectric screening, exhibit excitons with nanometer-scale Bohr radii and high binding energies (up to 500 meV). This facilitates device integration and room-temperature manipulation of excitons. Additionally, broken inversion symmetry and spin-orbit coupling in these materials introduce valley-spin degrees of freedom, offering new possibilities for information encoding and processing other than those based on charge and spin. Consequently, 2D exciton devices, such as circuits, switches, transistors, and sensors, based on semiconductor quantum well excitons, have garnered significant interest over the past decade.

Typically, exciton dynamics in 2D materials are passively regulated into a steady state using fixed substrate patterns to modulate the surface of monolayer TMDs, or steady-state strain fields to alter the band structure and photoluminescence (PL) properties of the material. In contrast, active control enables real-time, dynamically customizable exciton manipulation through external fields such as electric fields, mechanical strain, or optical manipulation, allowing precise adjustment and real-time feedback.

Surface acoustic wave (SAW) regulation is a method based on mechanical waves propagating along the surface of a solid to interact with 2D TMDs. By generating SAWs using interdigital transducers (IDTs), periodic piezoelectric and strain fields can be produced on 2D TMDs. These fields respond to the photoelectric properties of the 2D TMDs, thereby achieving dynamic regulation of exciton energy states and spatial positions (Fig. 2). The advantage of SAW regulation technology lies in its non-invasive, reversible, and real-time capabilities, enabling dynamic regulation without altering the intrinsic properties of the material. Particle irradiation introduces or regulates defects in TMDs using techniques such as ion irradiation, electron beams, gamma rays, neutrons, and lasers, significantly influencing the electronic and optical properties of the materials by creating atomic-scale defects. Specifically, these irradiation techniques introduce atomic-scale defects in 2D materials (Fig. 3), notably affecting the electronic and optical properties of the material (Fig. 4). Tip-induced regulation is a method that uses an atomic force microscopy (AFM) tip to precisely apply local strain to study and manipulate the dynamic behavior of excitons in 2D materials (Figs. 5‒7). By altering the strain state of the material, the bandgap of the material is affected, which then regulates its photoelectric properties. This method enables precise manipulation of exciton behavior in 2D TMDs at nanoscale and holds significant potential for the development of new optoelectronic and quantum devices. Phase transition regulation can cause variations in interface strain, electron density, and optical interference enhancement, which in turn affect the lattice vibration modes and PL emission intensity of the 2D TMDs semiconductor materials coated on top (Fig. 8). Phase transition regulation provides a new approach to control the physical properties of 2D TMDs without the need for chemical or mechanical treatment.

This study explores active regulation techniques of excitons in 2D TMDs, including SAW control, particle irradiation, tip-induced strain control, and phase change regulation. These techniques significantly enhance the performance of TMD-based optoelectronic devices by precisely controlling the generation and recombination processes of excitons. Previous studies have shown that SAW control can achieve dynamic capture and transport of excitons; ionizing radiation techniques optimize the PL properties of materials by introducing defects; tip-induced strain control precisely manipulates the exciton behavior at nanoscale; phase change regulation affects exciton characteristics by altering the interfacial strain, electron density, and light field distribution. Despite significant progress in the active regulation of TMDs excitons, their short lifetime and limited mobility still restrict their long-range transport on a 2D plane. Therefore, fabricating high-quality monolayer TMDs semiconductor materials and optimizing the exciton transport mechanism remain hot research topics. Moreover, the precise construction of exciton transport paths depends on advanced micro-nano processing technologies. The development of high-precision and large-scale production-capable processing technologies is crucial for the commercialization and practical application of exciton devices. Likewise, a deeper understanding of the 2D exciton physical mechanism requires further exploration. Further research and technological innovations are necessary to overcome current limitations and promote the practical use of exciton technology in optoelectronics and beyond, driving device development in the post-Moore era.