Organic light-emitting device including fluorescent compound and fluorescent compound

An organic light-emitting device comprising:

• a first electrode;
• a second electrode facing the first electrode;
• and
• an organic layer disposed between the first electrode and the second electrode,
• wherein the organic layer comprises an emission layer and a fluorescent compound,
• wherein the fluorescent compound comprises a 3n-π*-to-1π-π* energy transition from a 3n-π* excited state to a 1π-π* excited state,
• an energy level in a 1n-π* excited state of the fluorescent compound is greater than an energy level in the 1π-π* excited state of the fluorescent compound,
• the fluorescent compound emits a fluorescent light by radiative energy transition of an exciton in the 1π-π* excited state to a ground state,
• “3” in the expression “3n-π*” indicates a triplet state, and “1” in the expressions “1n-π*” and “1π-π*” indicates a singlet state, and
• the energy level in the 1n-π* excited state, the energy level in the 1π-π* excited state, and the energy level in the 3n-π* excited state are each independently calculated by using a time dependent-Density Functional Theory method that is structurally optimized at a level of CAM-B3LYP/6-311+G(d,p).