Characterization of the phase transition of a vanadium dioxide film on a silicon substrate through radiative emission in the mid-infrared

This paper shows a detailed analysis of the semiconductor-to-metal transition (SMT) in a vanadium dioxide (VO2) film deposited on silicon wafer. The vanadium dioxide phase transition is studied in the wide mid-infrared range 2-12 μm, by analyzing the transmittance and the reflectance measurements, and the calculated emissivity from the sample. The temperature behavior of the emissivity during the SMT put into evidence the phenomenon of the anomalous absorption in vanadium dioxide which has been explained by applying the Maxwell Garnett effective medium approximation theory. A strong hysteresis phenomenon of about 8°C has also been found for transmittance, reflectance and emissivity. Experimental results show how the use of these techniques represent a good tool for a quantitative measurement of the infrared properties in the MIR range.