Effect of Pt doping on the optoelectronic properties of vanadium dioxide

Pt-doped VO2(B) thin films were prepared on quartz glass substrates using 500 degrees C RF magnetron sputtering. The study explored the impact of varying Pt concentrations on the microstructure, surface morphology, and thermotropic phase transition properties of the VO2 films. X-ray diffraction analysis revealed that Pt doping altered the phase of the VO2 films from VO2(B) to VO2(M) under identical preparation conditions, with the intensity of the VO2(M) phase diffraction peaks decreasing as the doping concentration increased. Field emission scanning electron microscopy analysis demonstrated that the size of the island-like nuclei particles on the surface of the PtVO2 films increased with higher Pt doping levels. The thermotropic resistance of the Pt-VO2 films varied with temperature, with phase transition temperatures (TM) ranging from 47.1 degrees C to 52.3 degrees C, significantly lower than the 67.5 degrees C observed in the single-crystalline VO2 films. In situ infrared spectroscopy tests conducted on the Pt-3 samples indicated a 12.2 % reduction in the absorptivity at the thermal IR atmospheric window around lambda ti 8.9 mu m, showcasing properties of low IR emissivity while modulating the IR radiation. Overall, Pt-doped VO2 films exhibit thermotropic phase transition properties with significant potential for applications in new energy- efficient smart windows.