Fig. 2: Optimization of DEG cells with localized bottom electrodes.
a Schematic illustration and simplified circuit model of the localized bottom electrode (LBE) design for a DEG cell. The model mainly consists of bulk capacitor CB, device-induced parasitic capacitor CP,D, and circuit-induced parasitic capacitor CP,C. b Output voltage of the DEG cells with different electrode designs: (from left to right) global bottom electrode (GBE) overlapping top electrode (TE), GBE not overlapping TE, and LBE. c Output voltage of the LBE-DEG cells with different areas of the bottom electrode SBE (varying from 1 cm × 1 cm to 15 cm × 12 cm). d Finite element method (FEM) simulated potential distribution on cross-section of the DEG cells with different SBE. e Dependence of the bulk capacitance and parasitic capacitance on SBE. Within the gray shaded zone, SBE is equal to the maximum droplet spread area (SD,max) and the difference between the bulk capacitance and the parasitic capacitance is maximal. f Peak voltage Vpeak and average output power PRMS of the DEG cells with different SBE. Error bars represent the standard sample deviation. g Atomic force microscopy (AFM) images indicating surface roughness of (i) a PTFE film and (ii) a glass slide. h Experimental and simulated dependence of CB on SBE for PTFE and glass. i Average output power PRMS and energy harvesting efficiency EV of DEG cells developed in recent years12,23,25. Source data are provided as a Source Data file.
