Sr/Ag semitransparent cathodes for top emission organic light-emitting devices

We have developed a semitransparent cathode for the top emission organic light-emitting devices using a Sr/Ag double layer prepared by the thermal evaporation technique. The Sr (8–10 nm)/Ag (10 nm) cathode shows the transmittance of 55–76% in the visible spectral region and the sheet resistance of about 12 Ω/□. The underlying Sr layer affects the growing characteristics of Ag layer, resulting in high optical transparency. The bis[2-(2′-benzothienyl)-pyridinato-N,C3′]iridium(acetylacetonate) doped top emission electro-phosphorescent device with a Sr/Ag semitransparent cathode has been fabricated and studied.