Aerosol-assisted chemical vapor deposition of ZnS nanoleaves with optical sensitivity to gases

Abstract

A novel route for synthesizing ZnS nanostructured films via aerosol-assisted chemical vapor deposition (AACVD) is developed using the co-deposition of ((CH 3 -CH 2 ) 4 P 2 S 2 ) and ZnCl 2 reactants. Analysis of the films (600-700 nm thick) confirms the formation of hexagonal ZnS nanoleaves with non-stoichiometric sulfide defects at the surface, ∼93 % absorbance in the UV region (300-400 nm), and ∼60 % transmittance in the visible region (500-600 nm). Gas sensing tests conducted at room temperature (26 °C) under deuterium/halogen illumination, demonstrate the film's optical sensitivity to gases, in particular toluene and nitrogen dioxide, in the UV range (λ = 360 nm). In humid environments (40 % RH), the ZnS films exhibit a loss of the optical sensitivity to gases attributed to the formation of a ZnO overlayer on the ZnS surface. These results confirm the optical gas sensitivity of the AACVD co-deposited ZnS nanostructures, offering an alternative to both conventional resistance-based gas sensing approaches and traditional nanostructure synthesis methods.