A light-emitting device may include a first electrode, a second electrode, and a light-emitting layer therebetween. The first electrode may include a reflection layer and a metal oxide layer provided on the reflection layer. The metal oxide layer may be provided between the reflection layer and the light-emitting layer. The metal oxide layer may include molybdenum dioxide and an oxide of a group-V element, and a content of the group-V element to a total amount of the metal oxide layer may range from 2 at % to 10 at.