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

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 O3) 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 O3 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 lmW) at 100 cd m2.