Patent ID: 7629741

Claim:
An organic light-emitting device (OLED) comprising in the following order: a) an anode; b) a light-emitting layer disposed over the anode; c) a first electron-injecting layer disposed over the light-emitting layer, wherein the first electron-injecting layer includes at least one organic host material having a reduction potential less than −1.0 V vs. a Saturated Calomel Electrode selected from metal chelated oxinoid compounds and at least one dopant material capable of reducing the organic host material which is lithium; d) a second electron-injecting layer disposed in direct contact with the first electron-injecting layer, wherein the second electron-injecting layer includes at least one organic material having a reduction potential greater than −1.0 V vs. a Saturated Calomel Electrode and is selected from the chemical compounds having the structure of wherein R 1 -R 6 represent hydrogen or a substituent independently selected from the group consisting of halo, nitrile (—CN), nitro (—NO 2 ), sulfonyl (—SO 2 R), sulfoxide (—SOR), trifluoromethyl (—CF 3 ), ester (—CO—OR), amide (—CO—NHR or —CO— NRR′), substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted alkyl, where R and R′ are substituted or unsubstituted alkyl or aryl; or wherein R 1 and R 2 , R 3 and R 4 , or R 5 and R 6 , combine to form a ring structure including an aromatic ring, a heteroaromatic ring, or a nonaromatic ring, and each ring is substituted or unsubstituted; and e) a cathode disposed in direct contact with the second electron-injecting layer.