Patent ID: 7947974

Claim:
An OLED device comprising, in the following order, an anode, a hole transporting layer (HTL), a light-emitting layer (LEL) comprising a host molecule and a light-emitting molecule, an electron transporting layer (ETL) and a cathode and wherein: (i) the HTL comprises a hole transporting material (HTM) having an oxidation potential that is at least 0.2 V less positive than the oxidation potential of a predominant material in the ETL and does not contain any bonds having an energy less than 105 kcal/mol; and (ii) the ETL comprises an electron transporting material (ETM) having a reduction potential (RP etm ) relative to the reduction potential of a predominant material in the HTL (RP htm ) that meets the requirement of RP etm >(RP htm −0.05).