A compound of Formula Ir(L A ) x (L B ) y (L C ) z , wherein: x is 1 or 2; y is 1 or 2; z is 0 or 1; x + y + z = 3; L A has Formula I L B has Formula II and L C is a monoanionic bidentate ligand, wherein: Z 1 is N and Z 2 is C; Z 3 and Z 4 are each independently C or N, with one being C and the other N; R 1 , R 2 , R 3 , R 4 , R 11 , and R 12 are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aryl, heteroaryl, and combinations thereof, with at least one of R 1 , R 2 , and R 3 being not hydrogen or deuterium; at least one of R 11 and R 12 is aryl or heteroaryl; R 11 and R 12 together comprise two or more 6-membered aryl or heteroaryl rings, with the proviso that if the two or more 6-membered aryl or heteroaryl rings are next to each other they are always connected by a carbon to carbon single bond, and can be further joined by Y, with Y being selected from the group consisting of O, S, Se, CRR', SiRR', and NR; R A , R B , R C , R D , and R E each independently represents zero, mono, or up to a maximum number of allowed substitution to its associated ring; each of R, R', R A , R B , R C , R D , and R E is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and any two of R, R', R A , R B , R C , R D , and R E can be joined to form a ring. x is 1 or 2; y is 1 or 2; z is 0 or 1; x + y + z = 3; L A has Formula I L B has Formula II and L C is a monoanionic bidentate ligand, wherein: Z 1 is N and Z 2 is C; Z 3 and Z 4 are each independently C or N, with one being C and the other N; R 1 , R 2 , R 3 , R 4 , R 11 , and R 12 are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aryl, heteroaryl, and combinations thereof, with at least one of R 1 , R 2 , and R 3 being not hydrogen or deuterium; at least one of R 11 and R 12 is aryl or heteroaryl; R 11 and R 12 together comprise two or more 6-membered aryl or heteroaryl rings, Z 1 is N and Z 2 is C; Z 3 and Z 4 are each independently C or N, with one being C and the other N; R 1 , R 2 , R 3 , R 4 , R 11 , and R 12 are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aryl, heteroaryl, and combinations thereof, with at least one of R 1 , R 2 , and R 3 being not hydrogen or deuterium; at least one of R 11 and R 12 is aryl or heteroaryl; R 11 and R 12 together comprise two or more 6-membered aryl or heteroaryl rings, R A , R B , R C , R D , and R E each independently represents zero, mono, or up to a maximum number of allowed substitution to its associated ring; each of R, R', R A , R B , R C , R D , and R E is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and any two of R, R', R A , R B , R C , R D , and R E can be joined to form a ring. <EOS>