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 (WO3) 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:WO3 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 (3.1V), and high power efficiency (3.5lm∕W) at 100cd∕m2.