Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode

Transparent organic light emitting diodes were developed by using a thermally evaporable WO3/Ag/WO3 (WAW) as a transparent cathode. A thin Ag layer was introduced as an interlayer between the Li doped electron transport layer and the WAW electrode. A high transparency over 80% was obtained and electron injection was greatly improved by using the thin Ag interlayer between the Li doped layer and the WAW electrode. The driving voltage at 1000 cd/m(2) was only 4.5 V and the sheet resistance of the WAW electrode was as low as 12 Omega/rectangle. (C) 2008 American Institute of Physics.