Fabrication and characterization of reduced graphene oxide on MoS₂ film for IR detectors

Abstract Graphene has gained tremendous attention in the field of photonics and electronics because of its numerous outstanding properties including zero bandgap, exceptionally high crystal and electronic quality, high mechanical strength, and electrical conductivity. At the cutting edge of technology, graphene oxide–molybdenum disulphide hybrid structures have drawn tremendous attention for the development of high efficiency infrared (IR) detectors, where MoS 2 film is used for generation of photoelectrons, and reduced graphene oxide is used to enhance the carrier mobility. The production of graphene oxide (GO) in this work is done using a modified version of Hummer’s process, in which GO is thermally reduced for an hour at 350 °C to produce reduced graphene oxide (rGO). The appearance of X-ray diffraction peak, corresponding to (001) and (002) for GO and rGO, respectively confirms the crystalline nature of the materials. The Raman spectra of GO and rGO exhibit distinctive peaks located at 1,358 cm −1 and 1,597 cm −1 , which correspond to the D bands and G bands, respectively. The layered structure of rGO is examined by scanning electron microscopy. On the other hand, MoS 2 film was grown by the sulphonation of sputtered Mo film on silicon substrate. The characteristic peak of MoS 2 , corresponding to (002) plane, is observed around 2 θ = 14.1° whereas Raman characteristic bands are observed at 386 cm −1 (E 1 2g ) and 408 cm −1 (A 1g ). Afterwards, rGO layer was deposited on MoS 2 thin film. The highest current On/Off ratio of 45.8 was found under illumination of 1,060 nm IR source. Under illumination at a 1,060 nm IR wavelength, the device demonstrates a responsivity of 0.21 A W −1 and detectivity of 1.83 × 10 9 Jones.