Low-emitting transparent coatings based on transparent conductive oxides via a sol-gel routine
Matthias Rydzek, Matthias Reidinger, Christian Scherdel, Maria-Carla Arduini-Schuster, Jochen Manara
Enhanced sol-gel processes for the deposition of transparent conductive oxides (TCOs) such as tin doped indium oxide (ITO) on different substrates, using two different solutions, a “conventional” sol and a nanoparticle suspension, have been developed. The coatings were obtained by using the dipcoating method and a subsequent annealing process which can be attuned to the temperature stability of the substrate. To coat temperature-sensitive substrates such as polycarbonate (PC) for instance, based on the “conventional” sol via a precipitation process, nanoparticle suspensions could be achieved. These dispersed nanoparticle suspensions can be cured at ambient temperature by using ultraviolet radiation and result in transparent and infrared reflecting coatings, too. The lowest attained emittance in the infrared was below 0.20 for coated glass substrates, whereas the transparency in the visible spectral range could be kept at 0.80 and above. By varying the preparation parameters, the characteristics of the coatings could be controlled.
Keywords: Infrared-optical properties, electrical properties, thin-film, nanoparticle,low-emitting, sol-gel, transparent conductive oxides, indium tin oxide.