A method for synthesizing nanoparticles with a predetermined size at high or full yield comprises mixing a first precursor material comprising a first compound comprising a halide moiety and a metal or a metalloid, a second precursor material comprising a second compound comprising a polyatomic nonmetal, and a solvent. The method further comprises heating the mixture to colloidally form nanoparticles comprising the polyatomic nonmetal and the metal or metalloid. The halide moiety is selected such as to colloidally form the nanoparticles in a predetermined size range that is at least partially determined by this halide moiety.