VO2 thin film based highly responsive and fast VIS/IR photodetector

The VO2 (M1) thin film has attracted significant attention due to its abrupt semiconductor to metal transition (SMT) near room temperature and diverse optoelectronic applications. In this work, pure VO2 (M1) phase thin film has been grown on the silicon substrate using a pulsed laser deposition technique. The Raman spectroscopy results confirmed the deposition of pure VO2 (M1) phase thin film. The X-ray photoelectron spectroscopy (XPS) showed that the deposited vanadium oxide thin film is mainly composed of VO2. The field emission scanning electron microscopy (FESEM) showed a smooth, continuous, and well-covered surface morphology. The elemental composition analysis of the deposited thin film using energy-dispersive X-ray spectroscopy (EDX) exhibited the presence of V and O in the deposited thin film. The VO2 (M1) thin-film device with a simple planar structure displayed resistance change of more than two orders of magnitude with increasing and decreasing temperature displaying a sharp semiconductor to metal transition (SMT) behavior with a transition width of-10 C and transition temperature of-67 C; a property associated with VO2 (M1). The photo-detection results of the VO2 (M1) based device revealed a better response upon illumination with 650 nm light at 0.15 mW/cm(2) compared to 980 nm light at 0.34 mW/cm(2). The rise time (tr) and fall time (tf) of-1.57 and-1.64 ms were achieved upon illumination with 650 nm light at 0.15 mW/cm(2) while-1.67 and-4.12 ms upon illumination with 980 nm light at 0.34 mW/cm(2). The photo-responsivity has been measured as-353 mA/W and-78 mA/W for 650 nm and 980 nm light, respectively. The response time and responsivity of the phase pure VO2 (M1) thin film for the Visible and IR light has been significantly improved compared to the earlier reported vanadium dioxide thin films based photodetectors.