Abstract: An OLED device having an emission layer formed of an ambipolar phosphine oxide host material and a dopant, a hole transport layer in electrical communication with an anode, an electron transport layer in communication with a cathode, wherein the HOMO energy of the hole transport layer is substantially the same as the HOMO energy of the ambipolar host in the emission layer, and the LUMO energy of the electron transport layer is substantially the same as the LUMO energy of the ambipolar host in the emission layer.

Abstract: An OLED device having an emission layer formed of an ambipolar phosphine oxide host material and a dopant, a hole transport layer in electrical communication with an anode, an electron transport layer in communication with a cathode, wherein the HOMO energy of the hole transport layer is substantially the same as the HOMO energy of the ambipolar host in the emission layer, and the LUMO energy of the electron transport layer is substantially the same as the LUMO energy of the ambipolar host in the emission layer.

Abstract: A material comprising one or more phosphine sulfide moieties, the phosphorus atom of each of said phosphine moieties bonded by single bonds to at least two outer groups. The material is substantially purified and configured as part of a circuit. The material is preferably configured as an organic light emitting device having an anode layer, a cathode layer, and at least one organic layer interposed between the anode and cathode layer, wherein at least one of said organic layers comprises the substantially purified material having one or more phosphine sulfide moieties, and wherein the phosphorus atoms of each of said phosphine sulfide moieties is further bonded by single bonds to two outer groups.