Efficiency improvement in white organic light-emitting devices using simultaneous far- and near-field effects of silver nanoclusters

We investigated the simultaneous far-field (FF) and near-field (NF) effects on the performance of white organic light-emitting devices (WOLEDs) with an internal color conversation layer (CCL) by embedding single layer of silver nanoclusters (SNCs). Photoluminescent (PL) and electroluminescent (EL) intensity of devices with SNCs could be improved simultaneously via selecting appropriate distance of SNC from emissive molecule, matching spectra and deposition time of SNCs. A white light emission with CIE coordinates of (0.311, 0.381) was effectively realized. The current efficiency of proposed WOLED with SNCs had a 25.53% enhancement compared with that of reference device without SNCs, which was mainly ascribed to the SNCs-induced FF effect on PL of internal CCL and NF effect on EL of light emitting layer. In addition, the optimized device exhibited good color stability with applied bias. Furthermore, the chromaticity of plasmonic WOLEDs could be tailored through tuning the deposition time of SNCs.