The small contacting area between the metal conductor and the adjacent hydrogel functions as an electric double layer (EDL) and the electroluminescence layer functions as a capacitor too, as discussed earlier. In one example the first and third capacitors may have a capacitance of approximately 10^?1 F m^?2. The second capacitor (i.e. the electroluminescence layer) can have a capacitance of approximately 10^?7 F m^?2. From the equation above defining charge, it can be seen that majority of the charge is distributed on the electroluminescence layer since it has the smallest capacitance. The luminance of the electroluminescence layer is determined by the applied voltage on the particles of the electroluminescence layer.

FIG. 3 shows an example of the charge distribution across the electroluminescent device 100. As shown in FIG. 3 majority of the charge is concentrated around capacitor 202 and capacitor 206, due to the larger capacitance value of these capacitors. The capacitor 204 still attracts some charge. The electricity (i.e. charge) in the electroluminescence layer causes the electroluminescence layer to illuminate. The emitted light is a result of the recombination of excitons within the intrinsic heterojunction of the ZnS powders under an alternating current electric field, while the light wavelength is tuned by the dopants in the ZnS compound e.g. in the ZnS lattice.