Figure 1
Structure and operation of graphene-based vertical organic light-emitting transistors (Gr-VOLETs). (a) Schematic illustration of the structure and a SEM image of a cross-sectional slice of the Gr-VOLET with a single-layer graphene (SLG) source, stacked layers of organic functional channel layers, an Al drain, and an ITO gate separated with an Al2O3 gate dielectric (scale bar: 200 nm). (b) Light emission from a Gr-VOLET (4 mm × 2 mm, white squares) for three different gate voltages of VGS for a fixed source-drain voltage, VSD, of 3.8 V (see also Supplementary Video S1 and Supplementary Fig. S1b). (c) Relative electroluminescent spectra of a Gr-VOLET (solid curves) and of a corresponding control ITO-OLED (dotted curve). The molecular structure of Super Yellow (SY) is shown in the inset. (d) Temporal response of a Gr-VOLET with respect to the step gate voltages for a fixed VSD of 3.8 V.
