A light converting nanoparticle represented by Chemical Formula 1, AXx  Chemical Formula 1 wherein, in Chemical Formula 1, A comprises an alkaline metal element, an alkaline-earth metal element, or a combination thereof, X comprises a halogen element, and x is 1 or 2 and is selected such that Chemical Formula 1 is electrically neutral, and a dopant substituted for a portion of A, wherein the dopant comprises Tl+, In+, Pb2+, Bi3+, Ag+, Cu+, Eu2+, Mn2+, or a combination thereof, wherein a content of the dopant is less than 15 mole percent, based on a total moles of A, wherein the light converting nanoparticle has a particle diameter of less than or equal to about 100 nanometers, and the light converting nanoparticle has a structure, cubic structure, an orthorhombic structure, a rhombic dodecahedron structure, or a combination thereof.