Improved Efficiency of Light-Emitting Diodes by Plasmonic Nanopatterning of the Charge-Transfer Layer

Light-emitting diodes (LEDs) are presently not exploited at their full potential due to a multiple range of detrimental effects, such as generation of local modes, either surface plasmon-like or optical modes, ohmic losses, or total internal reflection caused by refractive index mismatch. Herein, the authors focus on LEDs with layered architectures by investigating the effects of interface nanopatterning occurring in the electron-transport layer on their overall performance. In particular, the integration of photonic nanostructures is investigated, while leaving the optical properties of the emitting material unchanged. The numerical results show that specifically designed nanopatterning can strongly contribute to the enhancement of the Purcell factor, outcoupling efficiency and thereby increase the external quantum efficiency by a factor of 2 with respect to the unpatterned structures. This demonstrates that, as in other light-emission technologies, morphological patterning is a valid strategy to improve the performance of LEDs.