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The use of photons to directly or indirectly drive chemical reactions has revolutionized the field of nanomaterial synthesis resulting in appearance of new sustainable laser chemistry methods for manufacturing of micro‐ and nanostructures. The incident laser radiation triggers a complex interplay between the chemical and physical processes at the interface between the solid surface and the liquid or gas environment. In such a multi‐parameter system, the precise control over the resulting nanostructures is not possible without deep understanding of both environment‐affected chemical and physical processes. The present review intends to provide detailed systematization of these processes surveying both well‐established and emerging laser technologies for production of advanced nanostructures and nanomaterials. Both gases and liquids are considered as potential reacting environments affecting the fabrication process, while subtractive and additive manufacturing methods are analyzed. Finally, the prospects and emerging applications of such technologies are discussed. [ABSTRACT FROM AUTHOR]

Halide perovskites have become a versatile platform not only for optoelectronic devices but also for modern optics and nanophotonics. Perovskite nano‐ and micro‐particles, metasurfaces, and photonic crystals demonstrate their applicability for directional enhanced photo‐ and electro‐luminescence, lasing, as well as for improving the performance of optoelectronic devices. However, ionic nature makes perovskites water soluble, while their high sensitivity to diverse chemicals complicates their patterning toward the formation of functional, high‐quality nanostructures. Here, recent progress on emerging laser technologies for processing and nanopatterning of halide perovskites, as well as their applications in designing advanced light‐emitting systems and controlling light at the nanoscale is overviewed. Special emphasis is made on the processes underlying the interaction of laser radiation with perovskites to disclose new avenues for their surface and volume modification with ultra‐high precision and a high degree of material's property control. [ABSTRACT FROM AUTHOR]

Upon systematic studies of femtosecond‐laser processing of monocrystalline Si in oxidation‐preventing methanol, it is shown that the electromagnetic processes dominating at initial steps of the progressive morphology evolution define the onset of the hydrodynamic processes and morphology upon subsequent multi‐pulse exposure. Under promoted exposure quasi‐regular subwavelength laser‐induced periodic surface structures (LIPSSs) are justified to evolve through the template‐assisted development of the Rayleigh‐Plateau hydrodynamic instability in the molten ridges forming quasi‐regular patterns with a supra‐wavelength periodicity and preferential alignment along polarization direction of the incident light. Subsequent exposure promotes fusion‐assisted morphology rearrangement resulting in a spiky surface with random orientation, yet constant inter‐structure distance correlated with initial LIPSS periodicity. Along with the insight onto the physical picture driving the morphology evolution and supra‐wavelength nanostructure formation, this experiments also demonstrated that resulting quasi‐regular and random spiky morphology can be tailored by the intensity/polarization distribution of incident laser beam allowing on‐demand surface nanotexturing with diverse hierarchical surface morphologies exhibiting reduced reflectivity at visible and shortwave‐IR wavelengths. Finally, the practical attractiveness of the suggested approach for improving near‐IR photoresponse and expanding operation spectral range of vertical p‐n junction Si photodetector operating under room temperature and zero‐bias conditions via single‐step annealing‐free nanopatterning is highlighted. [ABSTRACT FROM AUTHOR]

Here, we show that direct femtosecond laser nanostructuring of monocrystalline Si wafers in aqueous solutions containing noble-metal precursors (such as palladium dichloride, potassium hexachloroplatinate, and silver nitrate) allows for the creation of nanogratings decorated with mono- (Pd, Pt, and Ag) and bimetallic (Pd-Pt) nanoparticles (NPs). Multi-pulse femtosecond-laser exposure was found to drive periodically modulated ablation of the Si surface, while simultaneous thermal-induced reduction of the metal-containing acids and salts causes local surface morphology decoration with functional noble metal NPs. The orientation of the formed Si nanogratings with their nano-trenches decorated with noble-metal NPs can be controlled by the polarization direction of the incident laser beam, which was justified, for both linearly polarized Gaussian and radially (azimuthally) polarized vector beams. The produced hybrid NP-decorated Si nanogratings with a radially varying nano-trench orientation demonstrated anisotropic antireflection performance, as well as photocatalytic activity, probed by SERS tracing of the paraaminothiophenol-to-dimercaptoazobenzene transformation. The developed single-step maskless procedure of liquid-phase Si surface nanostructuring that proceeds simultaneously with the localized reduction of noble-metal precursors allows for the formation of hybrid Si nanogratings with controllable amounts of mono- and bimetallic NPs, paving the way toward applications in heterogeneous catalysis, optical detection, light harvesting, and sensing. [ABSTRACT FROM AUTHOR]

Amorphous silicon (α -Si) film present an inexpensive and promising material for optoelectronic and nanophotonic applications. Its basic optical and optoelectronic properties are known to be improved via phase transition from amorphous to polycrystalline phase. Infrared femtosecond laser radiation can be considered to be a promising nondestructive and facile way to drive uniform in-depth and lateral crystallization of α -Si films that are typically opaque in UV-visible spectral range. However, so far only a few studies reported on use of near-IR radiation for laser-induced crystallization of α -Si providing less information regarding optical properties of the resultant polycrystalline Si films demonstrating rather high surface roughness. The present work demonstrates efficient and gentle single-pass crystallization of α -Si films induced by their direct irradiation with near-IR femtosecond laser pulses coming at sub-MHz repetition rate. Comprehensive analysis of morphology and composition of laser-annealed films by atomic-force microscopy, optical, micro-Raman and energy-dispersive X-ray spectroscopy, as well as numerical modeling of optical spectra, confirmed efficient crystallization of α -Si and high-quality of the obtained films. Moreover, we highlight localized laser-induced crystallization of α -Si as a promising way for optical information encryption, anti-counterfeiting and fabrication of micro-optical elements. [ABSTRACT FROM AUTHOR]

• Au- decorated TiO 2 nanoparticles prepared by laser beam irradiation. • Decoration of TiO 2 surface with different amount of Au. • Sensing response of Au@TiO 2 nanomaterials towards different gases. • Au-nanoparticle dependent selectivity. This article reports on fabrication of activated TiO 2 and gold decorated TiO 2 prepared by irradiation with millisecond laser and on their gas sensing properties. Commercially available anatase TiO 2 was used as starting material whose nanoparticles were modified and decorated upon irradiating its water suspension by pulsed laser. Formation of Au nanoparticles was achieved by laser-induced reduction of Au(III) ions, followed by their deposition onto TiO 2 nanoparticle surface. In order to evaluate the effect of gold concentration in Au@TiO 2 nanocomposites on their sensing properties, two gold-containing samples with 1 and 5 wt% of Au were prepared. All nanomaterials were characterized by XRD, XPS and SEM methods and then tested as gas sensing devices towards a number of volatile compounds. XPS analysis revealed formation of oxygen vacancies and Ti3+ ions on the TiO 2 surface upon laser irradiation, while the latter defects disappeared after decoration with gold. Depending on the degree of Au loading, the samples demonstrated selectivity towards ammonia, acetaldehyde or benzene. [ABSTRACT FROM AUTHOR]