electrified solid–electrolyte interfaces (SEI) offer novel opportunities for the creation of
tuneable optical devices. We apply this concept to propose a fast electrotuneable, NP-based
Fabry–Perot (FP) interferometer, comprising two parallel transparent electrodes in aqueous
electrolyte, which form the polarizable SEI for directed assembly–disassembly of negatively
charged NPs. An FP cavity between two reflective NP-monolayers assembled at such …