Origin of light manipulation in nano-honeycomb structured organic light-emitting diodes†
The authors demonstrate a honeycomb structured organic light-emitting diode (OLED) with high enhancements greater than 2.0 fold and 2.3 fold in current efficiency and power efficiency, respectively. The dispersion relationships in both planar and nano-honeycomb structured OLEDs are calculated through numerical simulations utilizing the finite-difference time-domain method and measured through the electroluminescence spectra. There is good agreement between the numerically calculated and the experimentally measured dispersion relationships for the nano-honeycomb structured OLEDs. Improved light out-coupling efficiency is mainly attributed to the efficient extraction of the waveguide and the surface plasmon polariton (SPP) loss modes in the devices. Particularly, most of the extracted energy is verified to be originated from the SPP loss mode in honeycomb structured OLEDs.