Light emissive device having cathode comprising a codeposited mixed layer

US8415875B2 · kind B2 · utility

Assignee

• Cambridge Display Technology Limited · GB

Inventors

• Euan Smith · Cambridge, GB
• Matthew Roberts · Godmanchester, GB
• William Young · Dawsonville, US
• Clare Foden · Cambridge, GB

Key dates

• Filing date: Sep 22, 2011
• Grant date: Apr 9, 2013
• Expiry date: Sep 22, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K2102/3026

Abstract

An organic light emissive device comprising: a first electrode; a second electrode; and an organic light emissive region between the first and second electrodes comprising an organic light emissive material which has a peak emission wavelength, wherein at least one of the electrodes is transparent and comprises a composite of a charge injecting metal and another material which is codepositable with the charge injecting metal, the other material having a different refractive index to that of the charge injecting metal and wherein the other material has a lower degree of quenching at the peak emission wavelength than the charge injecting metal whereby quenching of excitons by the at least one electrode is reduced, the charge injecting metal comprising either a low work function metal having a work function of no more than 3.5 eV or a high work function metal having a work function of no less than 4.5 eV.