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

Abstract

Transparent organic light emitting diodes were developed by using a thermally evaporable $\mathrm{W}{\mathrm{O}}_3∕\mathrm{Ag}∕\mathrm{W}{\mathrm{O}}_3$ (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 $1000\mathrm{cd}∕{\mathrm{m}}^2$ was only $4.5\mathrm{V}$ and the sheet resistance of the WAW electrode was as low as $12\Omega ∕◻$ .