A method of manufacturing a light emitting device that includes providing a first electrode, forming a light emitting layer including quantum dots on the first electrode, forming an electron auxiliary layer on the light emitting layer, and forming a second electrode on the electronic auxiliary layer. The forming of the electron auxiliary layer includes forming an electron auxiliary layer including a plurality of metal oxide nanoparticles, and contacting the plurality of metal oxide nanoparticles with a base including a hydroxyl group (OH).