Electrospray Deposition of Uniform Thickness Ge₂₃Sb₇S₇₀ and As₄₀S₆₀ Chalcogenide Glass Films

Abstract

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two chalcogenide compositions are demonstrated: Ge 23 Sb 7 S 70 and As 40 S 60 , which have both been studied extensively for planar mid-infrared (mid-IR) microphotonic devices. In this approach, uniform thickness films are fabricated through the use of computer numerical controlled (CNC) motion. Chalcogenide glass (ChG) is written over the substrate by a single nozzle along a serpentine path. Films were subjected to a series of heat treatments between 100 °C and 200 °C under vacuum to drive off residual solvent and densify the films. Based on transmission Fourier transform infrared (FTIR) spectroscopy and surface roughness measurements, both compositions were found to be suitable for the fabrication of planar devices operating in the mid-IR region. Residual solvent removal was found to be much quicker for the As 40 S 60 film as compared to Ge 23 Sb 7 S 70 . Based on the advantages of electrospray, direct printing of a gradient refractive index (GRIN) mid-IR transparent coating is envisioned, given the difference in refractive index of the two compositions in this study. Video LinkThe video component of this article can be found at

New Candidate Multicomponent Chalcogenide Glasses for Supercontinuum Generation

“…As a candidate glass for SC applications is (primarily) defined by its optical properties and damage resistance, its compatibility with the planned manufacturing method to final form (planar films or fiber) must be considered. Films made from simple binary glasses tend to be compatible with thermal evaporation methods, and some more complicated (ternary) glasses are amenable to solution derived processing methods either as glass [77] or organic/inorganic hybrids [79], with [80] or without [81] dopants. As noted for bulk materials above, variations in the deposition methods of thin films with identical composition can lead to concomitant variations in optical properties; thus, proper design of the processing method is also an important consideration for SC material fabrication [68].…”

Comparison of solution processed As33S67 thin films deposited using primary amines of various aliphatic chain length

“…Second group of methods is based on the solubility of ChG in volatile organic bases and formation of thin films from glass solution -e.g. : spin-coating [8], dip-coating [9], electrospray [10] or spiral-bar coating [11]. In comparison with physical vapor deposition methods, solution processed thin film deposition methods offer advantage in the possibility of source solution doping (e.g.…”

Advances in infrared gradient refractive index (GRIN) materials: a review

“…These efforts, largely focused on multimaterial, chip-scale (Si) integration of ChGs for sensing applications, and formed the basis of further activities aimed at doping with nanoparticles or quantum dots whereby luminescent behavior could extend the optical functionality of the films. 84,85 To aid in the physical dispersion of such particles to create tailorable optical function without quenching, coating techniques were further optimized to develop an electrospray (ES) technique 86,87 whereby particles could be contained within aerosol droplets, which upon evaporation of solvent during deposition, particles would not undergo the typical agglomeration realized in spin coating and other coating techniques. Once optimized, ES was shown to be suitable for depositing multiple composition of ChG and enabled the systematic creation of multilayer films.…”