Thermal annealing effects on microstructural and thermo-optical properties of V/V2O5 alternating layers structure

• V x O y thin films were suggested as a thermometer material for microbolometer. • Effect of annealing on structural and thermo-optical properties was studied. • The high sensitive Photothermal Techniques were used for optical and thermal investigation. • Raman spectra for V x O y annealed for different times, were analyzed. • High sensitive Photothermal Techniques were used for thermo-optical investigation. In this work, the effect of annealing time on structural, optical, and thermal properties of V x O y used as functional material in microbolometer applications is studied. A suitable thermal annealing to three samples composed of eleven alternating layers of vanadium pentoxide (V 2 O 5 ) and vanadium (V) grown by a sputtering method is applied. These samples were annealed for 30, 40, and 50 min at 300 °C in O 2 atmosphere. Raman spectroscopy, Photothermal Deflection Technique “PDT” and Photothermal Deflection Spectroscopy “PDS“ have been employed respectively for microstructure, thermal and optical characterization for V x O y samples. The thermal annealing induces formation of multiphase identified as VO 2 , V 2 O 5 , and V 6 O 13 . Also, the studied films showed that the thermal conductivity increases with increasing annealing duration however the gap energy decreases. As important results compared to our previous work, an investigation of thermal and optical properties of vanadium oxide V 2 O 5 /V thin films having high (TCR) and low resistivity is presented.