A composition comprising a first compound, a second compound, and a third compound, wherein the first compound, the second compound, and the third compound are different from each other, the first compound satisfies one of Condition 1 and Condition 2 as described herein, and the second compound includes a compound represented by Formula 1:

wherein ring A 1 is a condensed cyclic group in which 3 or more cyclic groups are condensed with each other, and the 3 or more cyclic groups are each a C 5 -C 30 carbocyclic group or a C 1 -C 30 heterocyclic group; a1 is an integer from 1 to 5; b1 is an integer from 3 to 10; and L 1 , R 1 , and R 2 are as described herein.