Figure 4

Gate-bias-induced modulation of SLG work functions and operation mechanism of Gr-VOLETs. (a) Gate-bias-induced modulation of the work functions of SLG sources on the VOLET substrates. (b) Energy-level diagrams of Gr-VOLET1 for high, mid, and low Φs at three distinct values of VGS at a given VSD. Φ depicts the tunnelling barrier height for the hole injection. ED: Dirac point energy of the SLG source used.