A light emitting device includes an emission layer including a plurality of quantum dots, and an electron auxiliary layer disposed on the emission layer, the electron auxiliary layer to transport electrons to the emission layer, wherein the electron auxiliary layer includes a plurality of metal oxide nanoparticles, wherein the metal oxide nanoparticles include zinc and a dopant metal, wherein the dopant metal includes Mg, Mn, Ni, Sn, Al, Y, Ga, Zr, Ni, Li, Co, or a combination thereof, wherein the dopant metal in at least one of the metal oxide nanoparticles is included in the metal oxide nanoparticle to have a concentration gradient of the dopant metal.