A compound having a formula M(L A ) x (L B ) y (L C ) z : wherein the ligand L A has Formula I, wherein the ligand L B has Formula II, wherein the ligand L c has Formula III, wherein M is a metal having an atomic weight greater than 40; wherein x is 1, 2, or 3; wherein y is 0, 1, or 2; wherein z is 0, 1, or 2; wherein x+y+z is the oxidation state of the metal M; wherein X 1 to X 5 are each independently a carbon or nitrogen; wherein ring A is a 5- or 6-membered aromatic ring fused to the ring having X 1 ; wherein rings C and D are each independently a 5 or 6-membered carbocyclic or heterocyclic ring; wherein R 3 , R 4 , R c , and R D each independently represents none to a maximum possible number of substitutions; wherein each of R 3 , R 4 , R c , and R D , R x , R Y , and R z are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any adjacent substituents of R 3 , R 4 , R C , and R D , R X , R Y , and R Z are optionally joined or fused into a ring; wherein R 1 and R 2 are each independently selected from the group consisting of alkyl and cycloalkyl, wherein the alkyl and the cycloalkyl can be unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein R 1 is different from R 2 . wherein the ligand L A has Formula I, wherein the ligand L B has Formula II, wherein the ligand L c has Formula III, wherein M is a metal having an atomic weight greater than 40; wherein x is 1, 2, or 3; wherein y is 0, 1, or 2; wherein z is 0, 1, or 2; wherein x+y+z is the oxidation state of the metal M; wherein X 1 to X 5 are each independently a carbon or nitrogen; wherein ring A is a 5- or 6-membered aromatic ring fused to the ring having X 1 ; wherein rings C and D are each independently a 5 or 6-membered carbocyclic or heterocyclic ring; wherein R 3 , R 4 , R c , and R D each independently represents none to a maximum possible number of substitutions; wherein each of R 3 , R 4 , R c , and R D , R x , R Y , and R z are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any adjacent substituents of R 3 , R 4 , R C , and R D , R X , R Y , and R Z are optionally joined or fused into a ring; wherein R 1 and R 2 are each independently selected from the group consisting of alkyl and cycloalkyl, wherein the alkyl and the cycloalkyl can be unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein R 1 is different from R 2 . <EOS>