Electroluminescence Enhancement with Gold Nanorods in Eu‐Based Emission Organic Layer

Europium‐based coordination compounds possessing narrow luminescence bands are promising emissive materials for organic light‐emitting devices with high colour purity in the red spectral region. However, OLEDs with organic emissive layers based on lanthanides generally suffer from a slow recombination time (≈1 ms), which leads to a relatively low external quantum efficiency. Here, gold nanorods are employed with optimized resonant optical properties for the wavelength range 500–700 nm to modify photo‐ and electroluminescence from the Eu‐based emission layer. Three different emissive europium complexes with a photoluminescence quantum yield of up to 100 % in powder and up to 63% in thin film are used. The experimental results supported by theoretical simulations show that the introduction of gold nanorods in the emission layer results in a 54% increase in the OLED performance. Thus, the highest brightness of solution‐processed Eu‐based OLEDs is obtained using the Eu(dbm) 3 TDZP complex with incorporated gold nanorods.