Fig. 2: Dielectric properties of Pechini-derived CCTO thin films.
a Schematic (top panel) and top-view optical image (bottom panel) of MIM devices for C-V measurements. Scale bars: 100 μm. b Capacitance versus voltage with different frequencies for various CCTO samples. c Calculated k at 100 kHz as a function of films’ calcination temperatures. Inset: C versus frequency in the range of 100 kHz–1 MHz for various CCTO samples, showing flat curves to consider the distributed model for border traps. d Top-gate transfer characteristics of one monolayer graphene FET with a transferred CCTO-550 film (thickness: 8 nm) as top-gate dielectrics. Inset: Optical image of the dual-gate monolayer graphene FET with a bottom-gate length of 6.62 μm and top-gate length of 5.73 μm. Scale bars: 10 μm (inset). e Top-gate Dirac point voltage as a function of Vbg. The red dotted line shows linear fitting of the experiment data. The slope is −0.0037, corresponding to equivalent oxide thickness of 0.9 nm. f Statistics of top leakage currents from three types of dual-gated transistors with transferred, 15 nm thick CCTO-550 films as top-gate dielectrics.
