A quantum dot-polymer composite including a polymer matrix; and core-shell quantum dots dispersed in the polymer matrix, wherein the core-shell quantum dots include a semiconductor nanocrystal core including indium, zinc, and phosphorus and a semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core, the shell including zinc, selenium, and sulfur. The core-shell quantum dots do not include cadmium, the core-shell quantum dots are configured to emit green light, the core-shell quantum dots have a mole ratio of phosphorus to indium of greater than or equal to about 0.75, and the core-shell quantum dots have a mole ratio of zinc to indium of greater than or equal to about 35, and a method of producing the core-shell quantum dots, and a display device including a light emitting element that includes the quantum dot-polymer composite.