Figure 1.

Schematic representation of the (a) three electrode (spectro)electrochemical setup. The cell contains a Ag wire pseudoreference electrode, Pt sheet counter electrode, and the sample on a working electrode. The solution is typically a 0.1 M LiClO₄ acetonitrile electrolyte solution. The steady state absorption can be measured during the electrochemical measurements. (b) The ZnO film on the IDE with Li⁺ or Na⁺ as an electrolyte cation. The ions have intercalated into the ZnO QDs upon electron injection. The schematic includes the parallel (in-plane) and perpendicular (out-of-plane) flow of electrons. (c) The ZnO film on the IDE with K⁺, TMA⁺, TBA⁺, or TOA⁺ as an electrolyte ion. The ions occupy the voids of the film. The schematic includes parallel and perpendicular flow of electrons.