{"type": "FeatureCollection", "features": [{"id": "10.1002/adma.202402907", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-30T16:14:25Z", "type": "Journal Article", "created": "2024-05-17", "title": "Ultrafast Laser Processing of 2D Materials: Novel Routes to Advanced Devices", "description": "Abstract

Ultrafast laser processing has emerged as a versatile technique for modifying materials and introducing novel functionalities. Over the past decade, this method has demonstrated remarkable advantages in the manipulation of 2D layered materials, including synthesis, structuring, functionalization, and local patterning. Unlike continuous\uffe2\uff80\uff90wave and long\uffe2\uff80\uff90pulsed optical methods, ultrafast lasers offer a solution for thermal heating issues. Nonlinear interactions between ultrafast laser pulses and the atomic lattice of 2D materials substantially influence their chemical and physical properties. This paper highlights the transformative role of ultrafast laser pulses in maskless green technology, enabling subtractive, and additive processes that unveil ways for advanced devices. Utilizing the synergetic effect between the energy states within the atomic layers and ultrafast laser irradiation, it is feasible to achieve unprecedented resolutions down to several nanometers. Recent advancements are discussed in functionalization, doping, atomic reconstruction, phase transformation, and 2D and 3D micro\uffe2\uff80\uff90 and nanopatterning. A forward\uffe2\uff80\uff90looking perspective on a wide array of applications of 2D materials, along with device fabrication featuring novel physical and chemical properties through direct ultrafast laser writing, is also provided.Polarization is a fundamental property of electromagnetic waves that plays a key role in many physical phenomena and applications. Schemes to manipulate it are revisited with the emergence of metasurfaces, which have brought multi\uffe2\uff80\uff90functionalities straightforwardly. However, this has come at the expense of design complexity that relies strongly on field theory. Here, an ingenious strategy of modular design is proposed to construct subwavelength multifunctional polarization control devices. Chiral metasurfaces with different handedness are first proposed and regarded as modules. The versatile polarization controller can thus be obtained with the combination of different modules. These experiments demonstrate that the well\uffe2\uff80\uff90designed polarization controller possesses reconfigurable functionality, and various broadband polarization and amplitude regulation functions with high efficiency including arbitrary linear polarization rotation, asymmetric transmission effect, neutral\uffe2\uff80\uff90density\uffe2\uff80\uff90like filter, polarization beam splitter, etc., can be readily realized just by changing the cascaded modules. The physical mechanisms of the versatile polarization controller and chiral metasurface modules are both guaranteed by the Fabry\uffe2\uff80\uff93P\uffc3\uffa9rot\uffe2\uff80\uff90like resonances, which are theoretically verified via the transfer matrix method. It is envisioned that the modular concept will be of great benefit to designing compact multifunctional polarization controllers.Metal\uffe2\uff80\uff90free carbon electrodes with well\uffe2\uff80\uff90defined composition and smooth topography are prepared via sputter deposition followed by thermal treatment with inert and reactive gases. X\uffe2\uff80\uff90ray photoelectron spectroscopy (XPS) and Raman spectroscopy show that three carbons of similar N/C content that differ in N\uffe2\uff80\uff90site composition are thus prepared: an electrode consisting of almost exclusively graphitic\uffe2\uff80\uff90N (NG), an electrode with predominantly pyridinic\uffe2\uff80\uff90N (NP), and one with \uffe2\uff89\uff881:1 NG:NP composition. These materials are used as model systems to investigate the activity of N\uffe2\uff80\uff90doped carbons in the oxygen reduction reaction (ORR) using voltammetry. Results show that selectivity toward 4e\uffe2\uff80\uff90reduction of O2 is strongly influenced by the NG/NP site composition, with the material possessing nearly uniform NG/NP composition being the only one yielding a 4e\uffe2\uff80\uff90reduction. Computational studies on model graphene clusters are carried out to elucidate the effect of N\uffe2\uff80\uff90site homogeneity on the reaction pathway. Calculations show that for pure NG\uffe2\uff80\uff90doping or NP\uffe2\uff80\uff90doping of model graphene clusters, adsorption of hydroperoxide and hydroperoxyl radical intermediates, respectively, is weak, thus favoring desorption prior to complete 4e\uffe2\uff80\uff90reduction to hydroxide. Clusters with mixed NG/NP sites display synergistic effects, suggesting that co\uffe2\uff80\uff90presence of these sites improves activity and selectivity by achieving high theoretical reduction potentials while facilitating retention of intermediates.The terahertz (0.1\uffe2\uff80\uff9310\uffc2\uffa0THz) range represents a fast-evolving research and industrial field. The great interest for this portion of the electromagnetic spectrum, which lies between the photonics and the electronics ranges, stems from the unique and disruptive sectors where this radiation finds applications in, such as spectroscopy, quantum electronics, sensing and wireless communications beyond 5G. Engineering the propagation of terahertz light has always proved to be an intrinsically difficult task and for a long time it has been the bottleneck hindering the full exploitation of the terahertz spectrum. Amongst the different approaches that have been proposed so far for terahertz signal manipulation, the implementation of metamaterials has proved to be the most successful one, owing to the relative ease of realisation, high efficiency and spectral versatility. In this review, we present the latest developments in terahertz modulators based on metamaterials, while highlighting a few selected key applications in sensing, wireless communications and quantum electronics, which have particularly benefitted from these developments.Polarization is a fundamental property of electromagnetic waves that plays a key role in many physical phenomena and applications. Schemes to manipulate it are revisited with the emergence of metasurfaces, which have brought multi\uffe2\uff80\uff90functionalities straightforwardly. However, this has come at the expense of design complexity that relies strongly on field theory. Here, an ingenious strategy of modular design is proposed to construct subwavelength multifunctional polarization control devices. Chiral metasurfaces with different handedness are first proposed and regarded as modules. The versatile polarization controller can thus be obtained with the combination of different modules. These experiments demonstrate that the well\uffe2\uff80\uff90designed polarization controller possesses reconfigurable functionality, and various broadband polarization and amplitude regulation functions with high efficiency including arbitrary linear polarization rotation, asymmetric transmission effect, neutral\uffe2\uff80\uff90density\uffe2\uff80\uff90like filter, polarization beam splitter, etc., can be readily realized just by changing the cascaded modules. The physical mechanisms of the versatile polarization controller and chiral metasurface modules are both guaranteed by the Fabry\uffe2\uff80\uff93P\uffc3\uffa9rot\uffe2\uff80\uff90like resonances, which are theoretically verified via the transfer matrix method. It is envisioned that the modular concept will be of great benefit to designing compact multifunctional polarization controllers.The terahertz (0.1\uffe2\uff80\uff9310\uffc2\uffa0THz) range represents a fast-evolving research and industrial field. The great interest for this portion of the electromagnetic spectrum, which lies between the photonics and the electronics ranges, stems from the unique and disruptive sectors where this radiation finds applications in, such as spectroscopy, quantum electronics, sensing and wireless communications beyond 5G. Engineering the propagation of terahertz light has always proved to be an intrinsically difficult task and for a long time it has been the bottleneck hindering the full exploitation of the terahertz spectrum. Amongst the different approaches that have been proposed so far for terahertz signal manipulation, the implementation of metamaterials has proved to be the most successful one, owing to the relative ease of realisation, high efficiency and spectral versatility. In this review, we present the latest developments in terahertz modulators based on metamaterials, while highlighting a few selected key applications in sensing, wireless communications and quantum electronics, which have particularly benefitted from these developments.Metal\uffe2\uff80\uff90free carbon electrodes with well\uffe2\uff80\uff90defined composition and smooth topography are prepared via sputter deposition followed by thermal treatment with inert and reactive gases. X\uffe2\uff80\uff90ray photoelectron spectroscopy (XPS) and Raman spectroscopy show that three carbons of similar N/C content that differ in N\uffe2\uff80\uff90site composition are thus prepared: an electrode consisting of almost exclusively graphitic\uffe2\uff80\uff90N (NG), an electrode with predominantly pyridinic\uffe2\uff80\uff90N (NP), and one with \uffe2\uff89\uff881:1 NG:NP composition. These materials are used as model systems to investigate the activity of N\uffe2\uff80\uff90doped carbons in the oxygen reduction reaction (ORR) using voltammetry. Results show that selectivity toward 4e\uffe2\uff80\uff90reduction of O2 is strongly influenced by the NG/NP site composition, with the material possessing nearly uniform NG/NP composition being the only one yielding a 4e\uffe2\uff80\uff90reduction. Computational studies on model graphene clusters are carried out to elucidate the effect of N\uffe2\uff80\uff90site homogeneity on the reaction pathway. Calculations show that for pure NG\uffe2\uff80\uff90doping or NP\uffe2\uff80\uff90doping of model graphene clusters, adsorption of hydroperoxide and hydroperoxyl radical intermediates, respectively, is weak, thus favoring desorption prior to complete 4e\uffe2\uff80\uff90reduction to hydroxide. Clusters with mixed NG/NP sites display synergistic effects, suggesting that co\uffe2\uff80\uff90presence of these sites improves activity and selectivity by achieving high theoretical reduction potentials while facilitating retention of intermediates.Ultrafast laser processing has emerged as a versatile technique for modifying materials and introducing novel functionalities. Over the past decade, this method has demonstrated remarkable advantages in the manipulation of 2D layered materials, including synthesis, structuring, functionalization, and local patterning. Unlike continuous\uffe2\uff80\uff90wave and long\uffe2\uff80\uff90pulsed optical methods, ultrafast lasers offer a solution for thermal heating issues. Nonlinear interactions between ultrafast laser pulses and the atomic lattice of 2D materials substantially influence their chemical and physical properties. This paper highlights the transformative role of ultrafast laser pulses in maskless green technology, enabling subtractive, and additive processes that unveil ways for advanced devices. Utilizing the synergetic effect between the energy states within the atomic layers and ultrafast laser irradiation, it is feasible to achieve unprecedented resolutions down to several nanometers. Recent advancements are discussed in functionalization, doping, atomic reconstruction, phase transformation, and 2D and 3D micro\uffe2\uff80\uff90 and nanopatterning. A forward\uffe2\uff80\uff90looking perspective on a wide array of applications of 2D materials, along with device fabrication featuring novel physical and chemical properties through direct ultrafast laser writing, is also provided.