Radio-frequency and optically transparent radome de-icing materials: fluorine-doped tin oxide

Abstract

Ice-elimination systems are very common in radio-frequency (RF) structures like radomes.

Solution processed glass/fluorine-doped tin oxide/aluminum-doped zinc oxide double layer thin films for transparent heater and near-infrared reflecting applications

“…The band gap energies were estimated as 3.33 eV for glass/FTO/AZO heater and 3.95 eV for glass/FTO substrate. These values are in accordance with the previously reported values for FTO (3.17-4.25 eV) and FTO/AZO thin films in literature [42,44,68]. The higher visible range transmittance of double-layered structure compared to single FTO layer may be attributed to the graded refractive index profile of this device, i.e., air (n = 1)/AZO (n = 1.82)/FTO (n = 1.98) [69,70].…”

“…The increase in the temperature developed very gradually for all voltage values and a considerable rise was only achieved in case of 9 V. The temperature was saturated after a response time of 195 s (the required time for 90% of saturation temperature). Bare FTO coatings were studied previously in literature for their its THs characteristics [46,48,68,82], and a wide range of achievable surface temperatures (39-93 °C) were reported depending on the sample size, film thickness, fluorine doping ratio, production method, substrate type, and applied voltages. Therefore, it can be said that the heating performance of the FTO substrate used for the current study agrees with the previous literature.…”

“…The areal power density for this sample was increased to 2.04 W/cm 2 at 6 V and a saturation temperature of 141 °C was achieved. Depending on the referred reference (literature or commercial data), THs with power densities in the ranges of 0.077-0.15 and 0.4-0.77 W/cm 2 can be used for defogging and deicing applications, respectively [68,[86][87][88]. The amount of heat generated by the heater due to Joule effect is depending on the heater material, electrode geometry, the sheet resistance of the coating, and the level of operating voltage.…”