Full text loading...
(Steps 1-5) Schematic diagrams of the processes to fabricate the graphene/ZnO NW/graphene vertical sandwich device. (Step 6) Schematic diagram of the cross-section of the graphene/ZnO NW/graphene based sandwich structure UV detector.
(a) SEM image of graphene/ZnO NW/graphene sandwich structure. (b) Raman spectra collected at two different positions of P1 and P2 denoted in the Fig. 2(a) where there is a graphene sheet (P1) and the graphene is etched by O2 plasma (P2), respectively. Source-drain current of (c) the bottom layer graphene (A1 and A2 electrodes) and of (d) the top layer graphene (B1 and B2 electrodes) as a function of the back-gate voltage applied on the Si substrate.
(a) I-V characteristic of the graphene/ZnO NW/graphene device in dark. Inset: the equivalent electric circuit of the device. (b) I-V characteristics of the graphene/ZnO NW/graphene UV detector (electrodes B1 and A1) under illumination of a 325 nm He-Cd laser with incident power densities ranging from 0 to ∼100 μW μm−2. Inset: the relationship between photocurrent sensitivity and the UV illumination power. (c) Time dependence of the photocurrent with switching on/off the 325 nm UV laser illumination. The bias applied on the electrodes between B1 and A1 is 2 V. (d) Magnification of the detailed behavior of the photocurrent decay.
I-V curves of the graphene/ZnO NW/graphene device under different vacuum status.
Schematic illustration of the energy band diagram of the graphene/ZnO NW/graphene sandwich structure under different illumination conditions of (a) in dark, (b) under UV laser illumination, and (c) after UV laser is turned off.
Article metrics loading...