Cover Story：Wen XM, Bi YG, Yi FS, Zhang XL, Liu YF et al. Tunable surface plasmon-polariton resonance in organic light-emitting devices based on corrugated alloy electrodes. Opto-Electron Adv 4, 200024 (2021).

Organic light-emitting devices (OLEDs) are of interest due to their potential applications for full-color flat-panel display and solid-state lighting. High efficiency is one of key issues for its commercial applications. However, more than 80% photons in OLEDs are trapped by substrate modes, waveguide (WG) modes, and surface plasmon–polariton (SPP) modes. The substrate modes induced by the reflection of the glass substrate/air interface can be suppressed by modifying the back side of the substrate, and photons trapped in WG modes can be recovered by applying novel transparent electrodes to replace ITO. Periodic corrugations are used to excite SPP resonance, and corrugated metal electrodes can extract the photons trapped by SPP modes in OLEDs. Here, a tunable SPP resonance has been reported by a feasible method in OLEDs based on corrugated Ag-Al alloy electrodes. The excited SPP resonance induced by the periodic corrugations was precisely tuned by changing the composition ratios of the Ag-Al alloy electrodes. With an appropriate composition ratio of the corrugated alloy electrode, the photons trapped in SPP modes were recovered and extracted effectively, and 25% increasement in luminance and 21% enhancement in current efficiency were achieved in OLEDs with the corrugated Ag-Al alloy electrodes.