Effective deicing of vehicle windows and thermal response of asymmetric multilayered transparent-film heaters

Abstract For the effective deicing of the windows of electric vehicles, we fabricated asymmetric multilayered transparent (AMT) film heaters exhibiting a low resistance (5.4 Ω/sq.) and high visible transmittance (88%), resulting in the highest figure of merit (759) reported to date. Also, the simulated transmittance of the AMT films better matched the experimental results when considering the microstructure of the reaction layer between the Ga-doped ZnO and Ag layers. Herein, an unconventional approach considering heat transfer by conduction is described because heat loss from the thick glass (>3 mm) inevitably occurs in the real-world application of vehicle windows. We formulated and simultaneously solved two derivative heat transfer equations considering the thermal loss in the thick glass and heat transfer in the heating films to accurately predict the temperature of the outside glass. To verify our model, we performed a heating test by inserting heated windows in a small-scale automobile model and were able to accurately predict deicing time and heating rates.