LAUSR

Abstract The size effect of copper, gold and silver nanoparticles on green OLEDs with MNP-PEDOT:PSS as hole injection layer (HIL) and 4,4′-bis(9-carbazolyl)-biphenyl(CBP): Ir(MMPIPA) 2 (acac) as emissive material were analysed. The OLEDs performance was enhanced by copper, gold and silver NPs with 21, 20 and 55 nm, respectively. The external quantum efficiency ( η ex ) of green OLEDs with Au (20 nm: III) and Ag (55 nm: IV) has been enhanced by 60% and 64%: power efficiency ( η p ) enhanced by 46.9% and 38.7% and current efficiency ( η p ) enhanced by 50.0% and 72.2%, when compared with control device (I) respectively. In addition higher efficiencies was harvested from OLEDs with codoped NPs [Au (20 nm) -Ag (55 nm), L - 51,262 cd/m 2 ; η ex - 9.8%; η c - 35.3 cd A −1 and η p - 8.2 lm W −1 and Cu (21 nm) - Ag (55 nm), L - 49,856 cd/m 2 ; η ex - 8.3%; η c - 32.1 cd A − 1 and η p - 7.5 lm W −1 ]. The η ex , η p and η c of codoped green OLEDs with Au-Ag NPs was improved by 96.0, 67.3 and 96.1%, respectively, compared to control device. The size controlled NPs can synergistically enhanced OLEDs performances by improving the internal quantum efficiency.