Organic light-emitting device

An organic light-emitting device comprising:

• a first electrode;
• a second electrode facing the first electrode;
• m emission units stacked between the first electrode and the second electrode, each emission unit comprising at least one emission layer;
• and
• m−1 charge generating layers respectively located between two adjacent emission units among the m emission units, each of the charge generating layers comprising one n-type charge generating region and one p-type charge generating region,
• wherein m is an integer of 2 or more,
• at least one of the m emission units further comprises a hole transport region between the first electrode and the emission layer, and
• at least one of the p-type charge generating region and the hole transport region comprises a phosphate-containing compound.