Fig. 3: Dielectric performance of ultrathin Mn3O4 nanosheets.
From: Controllable synthesis of nonlayered high-κ Mn3O4 single-crystal thin films for 2D electronics
a Schematic and OM image of a dual-gate graphene (Gr) field-effect transistor (FET) with ultrathin Mn3O4 as the top gate dielectric on a SiO2/p-type (Si/p-Si) substrate. S, D, and TG represent the source, drain, and top gate, respectively. b Total resistance of a typical dual-gate graphene FET as a function of back-gate voltage (Vbg) at different Vtg values. Source-drain voltage (Vds) = 10 mV. c Relationship between the back gate Dirac point voltage of the Gr FET and Vbg. The slope of the linear fit represented by the red solid line is -0.0028. d Thickness dependence of Mn3O4 dielectric constant measured by dual-gate Gr FET and metal-insulator-metal (MIM) devices at 1 kHz. The inset shows the dielectric constant dependence on equivalent oxide thickness (EOT). The red dashed line indicates the fitting curve of dielectric constants at different thicknesses. e Ultraviolet-visible (UV) absorption spectrum of ultrathin Mn3O4. Inset: Corresponding Tauc plot, indicating the optical bandgap (Eg) of ultrathin Mn3O4. α, h, and ν respectively represent the absorption coefficient, Planck’s constant, and photon frequency. f Comparison of the bandgap and dielectric constant of ultrathin Mn3O4 with devices employing other gate dielectrics6,8,9,10,13,16,45,50,51,52,53,54,55.
