An electroluminescent device including a first electrode and a second electrode facing each other; a light emitting layer disposed between the first electrode and the second electrode; and an electron transport layer disposed between the light emitting layer and the second electrode. The light emitting layer includes a plurality of semiconductor nanoparticles, and the electron transport layer includes a plurality of zinc oxide nanoparticles, the zinc oxide nanoparticles further include magnesium and gallium.