ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

A compound of Formula Ir(LA)x(LB)y(LC)z is provided, where the first ligand LA comprises a structure of Formula I, the ligand LB comprises a structure of Formula II, and the ligand LC is a bidentate ligand. In the compound, each of A1 to A8, X1 to X4, Z1, and Z2 is C or N; at least one of X1 to X4 is N, or at least one RA is electron withdrawing group, a silyl group, a germyl group, a heteroalkyl group, a cycloalkyl group, a hetrocycloalkyl group, an alkyl group having three or more carbon atoms, or combinations thereof; Y is a linking group; moiety C is a monocyclic ring or a polycyclic fused ring system; and each R, R′, R1, R2, R3, R4, RA, RB, RC, and RD is hydrogen or a General Substituent defined herein. Formulations, OLEDs, and consumer products containing the compound are also provided.