Composition, and electronic device and organic light-emitting device comprising same

The present specification relates to a composition, and an electronic device and an organic light-emitting device comprising the same, the composition comprising two or more compounds represented by Chemical Formula 1 and having different deuterium substituents, the deuterium number of the isotope having the highest isotope content per mass number among the two or more compounds having different deuterium substitution numbers is 13 or more. 本说明书涉及组合物以及包含其的电子器件和有机发光器件，所述组合物包含由化学式1表示并且具有不同的氘取代数的两种或更多种化合物，其中，在所述组合物中，具有不同的氘取代数的两种或更多种化合物中的具有最高的每质量数同位素含量的同位素的氘数为13或更大。