fig2

Figure 2. Luminescence principles applied to ion-conductive stretchable light-emitting devices. (A) ACEL Device: hot-electron impact excitation under a high-voltage AC electric field; (B) LEC Device: in situ P/N electrochemical doping and radiative recombination under a DC bias; (C) ECL Device: luminescence via the co-reactant pathway triggered by interfacial charge transfer; (D) EFC Device: fluorescence switching driven by redox-state transitions. ACEL: Alternating-current electroluminescence; LEC: light-emitting electrochemical cell; ECL: electrochemiluminescence; EFC: electrofluorochromism; hv: photon; P/N: p-type/n-type electrochemical doping; F_red: reduced state of the fluorophore; F_OX: oxidized state of the fluorophore; AC: alternating current.