Laser-induced phase transitions in 2D materials: from microscopic mechanisms to device applications

Two-dimensional (2D) materials exhibit a rich variety of crystal phases, which impart distinctly different electrical conductivity, optical response, and catalytic activity. This diversity makes phase engineering a core strategy for on-demand property tuning in 2D materials. To date, various phase engineering strategies have been developed, including chemical intercalation, strain engineering, and electrostatic gating. These approaches offer distinct advantages for specific scenarios, but each is also subject to intrinsic limitations, such as the introduction of extrinsic species, restricted modulation range, or limited compatibility with fabrication processing. Laser-induced phase transition (LIPT) has emerged over the past decade as a complementary route that addresses some of these constraints. Owing to the high temporal resolution, localized energy deposition, and non-equilibrium processing capability, LIPT can drive phase transitions on timescales ranging from femtoseconds to nanoseconds, while the spatial resolution, phase purity, and long-term stability remain active areas of investigation. This review systematically summarizes recent advances in LIPT applied to 2D materials. The underlying mechanisms, including thermally driven, electronically excited, and coherent-phonon-mediated transitions, are discussed. The regulation strategies of LIPT in terms of optical field, field assistance, and spatial field are also systematically discussed. Finally, the cutting-edge device applications enabled by LIPT are explored in depth, by which the future developments and applications are prospected.