Fig. 4
Performance of the hybrid graphene/Ti2O3 photodetector. a Id − Vd curves of the hybrid graphene/Ti2O3 photodetector measured in dark and under quantum cascade laser illumination (λ: 10 µm; power: 2 mW/cm2); the gate voltage is 80 V. The channel size is 10.8 µm × 19.5 µm. b Corresponding photocurrent of the hybrid graphene/Ti2O3 photodetector plotted as a function of bottom gate voltage. c Temporal response of the device to the illumination of 10 μm laser. d Responsivity of the hybrid graphene/Ti2O3 photodetector measured at different illumination wavelengths in the mid-infrared regime. The high responsivity measured in the wavelength regime from 4.5 to 10 μm demonstrated the broadband operation of the hybrid graphene/Ti2O3 photodetector. Error bars represent standard deviation. e Time-dependent photocurrent of the hybrid graphene/Ti2O3 photodetector with monolayer, bilayer and trilayer graphene. In the measurements of (c) and (e), the laser power was kept at 2 mW/cm2, and the source-drain voltage (Vd) and gate voltage (Vg) were kept at 2 mV and 80 V, respectively. f Noise spectra of monolayer, bilayer and trilayer graphene hybrid photodetectors as a function of frequency measured at a constant bias voltage of 5 mV. All the current noises show a typical trend of S~1/fα with α = 1. g Photocurrents of hybrid graphene/Ti2O3 photodetectors with different sizes of Ti2O3 nanoparticles measured under 10 µm laser illumination. The measurement parameters are the same as in Fig. 4c, d. Error bars represent standard deviation. h Comparison of the performance of the hybrid graphene/Ti2O3 photodetector with the state-of-the-art
