Electrothermal Performance of ATO-FTO Bilayer Films Prepared by Ultrasonic Spray Pyrolysi.

To improve the electrothermal performances of FTO based films, an ultrasonic spray pyrolysis method was applied to prepare ATO-FTO bilayer films on quartz substrates. The influence of the ATO film thickness on the structure, surface morphology and electrothermal performance of the bilayer films was conducted. Experimental results demonstrate that the prepared bilayer films are highly crystallized with a tetragonal rutile structure. As the thickness of the ATO film layer increases, the orientation along the (200) crystal planes of the film increases. The grain morphology of the film surface changes from a pyramidal shape to blocks gradually. Moreover, the square resistance of the film decreases from 11.03 Ω/sq to 4.75 Ω/sq as the thickness of the ATO film increase from 210 nm to 860 nm. The electric heating test results prove that the electrothermal performance of the bilayer films has been significantly improved. Comparing to the maximum equilibrium temperatures of 265.7 °C and 210 °C at a 20 V bias voltage for FTO and ATO films, a temperature as high as 440 °C can be achieved for ATO-FTO bilayer films with the ATO layer of 860 nm. Besides, the heating efficiency is 3.04x10^-4 W/(°C⋅mm²) for ATO-FTO bilayer films, indicating the ATO-FTO bilayer has excellent electrothermal performance with thermal stability [ABSTRACT FROM AUTHOR]