<title>Holographic gratings recorded by photodeposition of inorganic colloids</title>

Abstract

Surface photodeposition is a photon assisted process, by which thin films can be formed on substrates immersed in colloidal solutions. Holographic gratings of various spatial frequencies have been recorded by photodeposition of amorphous selenium colloids. The holographic surface relief grating formation is described in relation to the modulation transfer function of colloidal photodeposition. Spatial frequencies of about 1 500 lines/mm can be recorded with amorphous selenium, whose colloidal particle sizes range from 30 to 80 nm.

“Smart” Surface Dissymmetrization of Microparticles Driven by Laser Photochemical Deposition

“…Finally, considering our spherical cap model, the temporal behavior of the thickness h on top of the chromate layer can be directly deduced from the radius growth rate by the relation h = [(1 − cos θ)/sin θ] R , where θ is the “contact angle” at the perimeter. We expect h / R ≲ 0.1, as already measured in photodeposited surface relief gratings. , This is qualitatively confirmed by the side view of the beam-centered bead presented in Figure .…”

“…Furthermore, laser light offers strong localization in excitation, spectral selectivity in molecule activation, and ease of manipulation. While most experiments are realized in gas phases, photochemical deposition in liquids is very appealing because (i) it can be applied to a broad range of precursors, including molecular compounds, (ii) light energy conversion is high because the material density is larger than that of a gas phase, and (iii) production is experimentally easy.…”

Patterning and Substrate Adhesion Efficiencies of Solid Films Photodeposited from the Liquid Phase

“…Finally, experiments are extremely simple to set up because photodeposition is performed in classical homemade tight cells. This flexibility offers the opportunity to deposit a large variety of materials: noble metals (such as Au, , Ag, , Pd, Pt, , or Cu), semiconductors (such as CdS or ZnS, − CdSe or ZnSe, , (Bi, Sb) 2 S 3 , Se x Te 1− x , InS, PbS, Cu x S, CuInS 2 , Sd 1− x Zn x S, FeS x O y ), metal oxides and hydroxide (CrO 2 , Cr(OH) 3 , MnO 2 , SnO 2 , ZnO), polymers, and bio-organic or molecular complexes. , Moreover, irradiating solutions with a well-defined light intensity distribution makes it possible to write in a single step a large variety of patterns in serial (dot and line assemblies, for example) and in parallel (such as holographic gratings) onto both flat and curved solid substrates in contact with the photosensitive solution. Laser light thus behaves as a “smart” pencil, which tailors the material deposition by simply modifying the excitation wavelength, the intensity distribution, and its spatial extension .…”

Universal behavior of photochemical deposition in liquid solutions driven by a one-photon transition

“…Moreover, due to large photoabsorption cross sections, the process generally requires very moderate beam intensities, thus preventing thermal decomposition. This flexibility 12 offered the opportunity to deposit a large variety of products ranging from metals (gold 13,14 , platinum 15 , silver 16 , palladium 17 , copper 18 , nickel 19 , selenium 20 , lanthanides 21 ), semiconductors 28 ), to bio-organic materials 29 and molecular compounds (Prussian blue 30 , porphyrins 31 , polydiacetylene 32 , poly(methylsilixane) 33 ), onto various types of substrates (semiconductors 34,35 , metal oxides 36 , polymers 37 ). Finally, by irradiating liquid solutions with a well-defined light intensity distribution, it is possible to write in single step and contactless conditions various types of patterns (such as dot 38 and line 39 assemblies, or more intricate structures like holographic gratings 40 ) onto flat 41 or curved 42 substrates.…”