Highly power efficient organic light-emitting diodes with a p-doping layer

Abstract
In this letter, the authors demonstrate p - i - n organic light-emitting diodes(OLEDs) incorporating a p -doped transport layer which comprises tungsten oxide ( W O 3 ) and 4 , 4 ′ , 4 ″ -tris( N -(2-naphthyl)- N -phenyl-amino)triphenylamine (2-TNATA) to replace the volatile tetrafluro-tetracyanoquinodimethane. The authors propose the 2 - TNATA : W O 3 composition functions as a p -doping layer which significantly improves hole injection and conductivity of the device that leads to the fabrication of tris(8-quinolinolato)aluminum based p - i - n OLEDs with long lifetime, low driving voltage ( 3.1 V ) , and high power efficiency ( 3.5 lm ∕ W ) at 100 cd ∕ m 2 .