A quantum dot including a multi-component core including a first semiconductor nanocrystal including indium (In), zinc (Zn), and phosphorus (P) and a second semiconductor nanocrystal disposed on the first semiconductor nanocrystal, the second semiconductor nanocrystal including gallium (Ga) and phosphorus (P) wherein the quantum dot is cadmium-free and emits green light, a mole ratio (P:In) of phosphorus relative to indium is greater than or equal to about 0.6:1 and less than or equal to about 1.0, and a mole ratio (P:(In+Ga)) of phosphorus relative to indium and gallium is greater than or equal to about 0.5:1 and less than or equal to about 0.8:1, a quantum dot-polymer composite pattern including the same, and a display device.