A light-emitting device including a first electrically conducting layer, a second electrically conducting layer, and a light-emitting layer disposed between the first electrically conducting layer and the second electrically conducting layer, the light emitting layer including light emitting nanostructures, wherein the light emitting layer is configured to emit green light, the light-emitting layer do not include cadmium, lead, or a combination thereof, the light emitting nanostructures include a first semiconductor nanocrystal including a Group III-V compound and a second semiconductor nanocrystal including a zinc chalcogenide, the Group III-V compound includes indium, phosphorus, and optionally zinc, the zinc chalcogenide includes zinc, selenium, and sulfur, the light emitting nanostructures exhibit a zinc blende structure, and in a two dimensional image of the light emitting nanostructures obtained by an electron microscopy analysis, an average value of squareness of the light emitting nanostructures is greater than or equal to about 0.8.