Announcing a new publication from Opto-Electronic Manufacturing; DOI 10.29026/oem.2026.260005
Since the discovery of graphene, the family of 2D materials has exhibited a rich diversity of phase structures. Taking 2D transition metal dichalcogenides (2D-TMDs) as an example, the 2H phase exhibits semiconducting property, while the 1T' phase possesses metallic character and even superconductivity, providing an ideal physical platform for constructing homojunctions, memristors, and ultrafast optical switches. However, achieving tunable phase transitions with high spatial resolution and without the introduction of impurities is still challenging. Traditional phase-transition engineering strategies have limitations in both microscopic mechanisms and process compatibility. Chemical intercalation readily introduces impurities and degrades the electrical properties of materials; strain and electrostatic doping make it difficult to achieve large-area uniform phase transitions; and CVD cannot perform in-situ regulation of already-fabricated devices. To overcome these bottlenecks, laser-induced phase transition (LIPT) technique, with the advantages of being non-contact, mask-free, and offering high spatial resolution, has been developed. Elucidating the atomic-scale microscopic mechanisms of LIPT and developing high-spatial-resolution, patternable, and precise phase engineering strategies become the core topics for fundamental research and industrial application of novel 2D devices.
This article reviews the development of LIPT in 2D materials, providing a comprehensive overview of the microscopic mechanisms, regulation strategies, cutting-edge applications, and future challenges. It systematically summarizes three core phase transition mechanisms including thermal driving, electronical excitation, and coherent-phonon mediation, by which the essence of light-matter interactions from the atomic and electronic levels is elucidated. This review highlights the phase-transition engineering strategies of LIPT covering laser parameter regulation, external physical field assistance, and spatial light field manipulation, followed by the cutting-edge device applications. Finally, the future development and application prospects of LIPT in 2D materials is outlooked.
Article Highlights
- The article reviews the full-chain journey of LIPT in 2D materials, from fundamental phenomenon to device applications, clearly delineating the core stages such as theoretical foundation, mechanism elucidation, regulation strategies, and device applications, thereby clarifying the research development.
- The article integrates three microscopic mechanisms, covering thermally driving, electronical excitation, and coherent-phonon-mediation, revealing from the physical mechanisms of atomic rearrangement and band structure reconstruction in laser-2D material interactions.
- The article summarizes three regulation strategies, i.e., laser parameter regulation, external physical field assistance, and spatial light field manipulation, as well as clarifies the advantages and limitations of each in terms of spatial resolution, phase transition selectivity, and process efficiency.
- The article explores the applications of LIPT in cutting-edge fields such as optoelectronic devices, nonlinear optics, surface-enhanced Raman spectroscopy, catalysis, and information storage, systematically demonstrating the extraordinary unique advantages in in-situ, non-destructive, and high-precision customization of 2D material properties.
- The article proposes the schemes including multi-scale in-situ characterization, heterostructure encapsulation engineering, multi-beam parallel direct writing, and machine learning-assisted screening, providing feasible solutions for industrialization of LIPT.
Keywords: 2D materials, laser-induced phase transition, thermal effect, nonthermal phase transition, femtosecond-laser processing, phase engineering
