Effect of thickness on the optical, structure, and electrical properties of vanadium oxide thin films

Vanadium pentoxide (V₂O₅) thin films on glass, made using RF magnetron sputtering at power level (100 W) and thicknesses (150, 250, and 350 nm) at room temp have been prepared. We checked out how film thickness impacts the structure, light interaction, and electrical behavior of the V₂O₅ films. X-ray diffraction (XRD) showed that an orthorhombic V₂O₅ thing formed. Atomic force microscopy (AFM) showed surfaces got smoother and less rough as the films got thicker. UV–Vis spectroscopy showed less light got through as films thickened. The optical band gap got wider, going from 2.2 eV (150 nm) to 2.4 eV (250 nm), and then 2.6 eV for the 350 nm film. Electrical stuff: resistivity went way down from 1.4 × 10-3 Ω.cm at 150 nm to 2 × 10-4 Ω.cm at 350 nm. Conductivity went up from 1 × 10³ (Ω.cm)-1 to over 7 × 103 (Ω.cm)-1. Hall effect results said all films were n-type, probably because of oxygen gaps. Basically, how thick these V₂O₅ films are really changes how they work. This is key if you wanna use them in optoelectronic devices, sensors, and electrochromic systems.