High performance UV photodetector based on metal-semiconductor-metal structure using TiO2-rGO composite

Abstract

Here, TiO2-reduced graphene oxide (rGO) has been reported as a very effective UV photodetection material. The TiO2-rGO composite samples with different ratios were prepared by using a green synthesis technique and an MSM photodetector was fabricated on SiO2-Silicon wafer. The XRD diffraction of TiO2-rGO composite reveals the presence of both anatase and rutile phase of TiO2, whereas Raman spectra of the sample indicate the increase of ID/IG ratio with the increase of rGO percentage. A high responsivity of 7.712 A/W, high detectivity of 7.92 × 1013 cm Hz.5W−1 with low response time of 43 ms were measured at UV illumination of 370 nm wavelength and power density of 10 μW/cm2 with TiO2-rGO composite device due to having slow recombination. A very low dark current of 7.3 nA of the device contributes to the reduced noise equivalent power. The low cost fabrication and high performance of the device assure wide commercial and military use.