Enhanced visible and IR light-sensing performance of photoconductive VO2 (M1) nanorods thin film

Abstract

In this article, we report on the enhanced photo-response of VO2 (M1) nanorods (NRs) thin film upon exposure to visible and near Infrared (NIR) light. The growth of photoconductive VO2 (M1) NRs thin film has been carried out using a pulsed laser deposition (PLD) technique. Field emission scanning electron microscopy (FESEM) showed the formation of NRs-like structures on the deposited thin film. The semiconductor-to-metal transition (SMT) properties at ∼64.8 °C and ∼59.8 °C during the heating and cooling cycle respectively confirm the deposition of VO2 (M1) thin film. The formation of VO2 (M1) thin film is also validated by Raman spectroscopy and X-ray diffraction (XRD) techniques. The photoconductivity of the pulsed laser deposited VO2 (M1) NRs thin film has been studied using the simple planar geometry upon exposure to the visible light (650 nm) and NIR light (980 nm) at 2 V and 5 V bias voltages. The estimated rise time and fall time of the photoconductive VO2 (M1) NRs thin films were about 1.88 ms and 1.9 ms upon exposure to the visible light and 1.89 and 2.4 ms upon exposure to the NIR light respectively. The photo-responsivity values of ∼1120 mA/W and ∼138 mA/W have been achieved for the visible and NIR light respectively at 5 V bias voltage. The photoconductive VO2 (M1) NRs thin film reveals highly responsive and fast visible and NIR light-sensing performance with simple planar geometry (Ag/ VO2 (M1) NRs thin film/Ag).