All-Solution-Processed Multilayered White Polymer Light-Emitting Diodes (WPLEDs) Based on Cross-Linked [Ir(4-vb-PBI)(acac)].

All-solution-processed multilayered white polymer light-emitting diodes (WPLEDs) are promising candidates for low-cost and large-area flexible full-color flat-panel displays and solid-state lighting. However, it is still challenging to improve their performance. In this work, based on an elegant strategy of orthogonal materials, the utilization of the cross-linked Ir polymer film ( = -vinyl-carbazole; = 1-(4-vinylbenzyl)-2-phenyl-1-benzo[]imidazole; and = acetylacetone) as the emitting layer (EML) between a hydrophilic polymer film poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) () as the hole injection layer (HIL) and a hydrophobic polymer film ( = 2-(4-(-butyl)phenyl)-5-(4'-vinyl-[1,1'-biphenyl]-4-yl)-2,5-dihydro-1,3,4-oxadiazole) as the electron transport layer (ETL) led to the successful fabrication of reliable all-solution-processed multilayered WPLEDs. The device exhibits a η of 18.19 cd/A, a η of 8.16 lm/W, and a η of 9.32% with stable white light (Commission International De L'Eclairage (CIE) coordinates = 0.269-0.283, = 0.317-0.330; corrected color temperatures (CCTs) of 7237-8199 K, and CRIs (color rendering indices) of 63-72) under a wide applied-voltage range. Its high performance, especially with record efficiencies among those of reported all-solution-processed WPLEDs, renders cross-linked Ir polymers a new platform to all-solution-processed multilayered WPLEDs.