Wet chemical deposition of multifunctional conducting coatings made with a nanocomposite suspension

Abstract

A nanocomposite suspension made of redispersable crystalline ln 2O3:Sn (ITO) nanoparticles and a hybrid organic-inorganic additive was prepared to obtain single 600nm-thick, transparent, electrically-conducting layers. The rheology of the suspension was adjusted so that the formulations could be used to coat different glass and polymer substrates and foils using wet chemical deposition techniques such as spin coating, dip coating, spray coating and web coating. The optical properties (transmission, reflection, absorption) showed that the layers transmitted more than 87% in the visible range, acted as infrared (IR)-shielding coatings for (λ > 1.5µm, and effectively reduced the intensity of solar light (Air Mass (AM) 1.5 Global solar spectrum). At the same time, the layers acted as UV blockers for wavelengths less than 400nm, protecting the polymer substrates and foils from degradation when exposed to UV irradiation. The layers exhibited a high conductivity (σ∼ 1100Sm-1) which made them useful for electrostatic and antistatic purposes as well as for devices that require a transparent conducting coating with sheet resistance higher than a few kΩ. Furthermore, the layers showed excellent adhesion on all substrates and high resistance against abrasion and weathering degradation, results that are quite promising with respect to their outdoor use.