Figure 4.

(a) The electrostatic model of the device represented by two electrical double layer capacitors for each interface. The voltage drop across the device is inversely proportional to the EDL capacitor for each interface. The voltage of the bulk ionic liquid is determined by the balance between these capacitances. (b–d) The three cases of ion size asymmetry and different charge distribution schemes. (b) Large cation (THTDP⁺) and small anion (Cl^–) both with a concentrated charge distribution. (c) Cation (AMIM⁺) and anion (TFSI^–) have a concentrated and delocalized charge, respectively, but with equivalent ion size. (d) Small cation (SEt3⁺, concentrated charge) and large anion (TFSI^–, delocalized charge distribution). The graphs show the modulation of the emissivity as a function of voltage for each case.