| abstract |
The invention provides an OLED device comprising, in the following order, a 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 an cathode and wherein: n (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 the predominant material in the ETL and does not contain any bonds having an energy less than 105 kcal/mol; and n (ii) the ETL comprises an electron transporting material (ETM) having a reduction potential (RP etm ) relative to the reduction potential of the predominant material in the HTL (RP htm ) that meets the requirement of RP etm >(RP htl −0.05). n Devices of the invention provide improvement in features including efficiency. |