A doping method using a three-step synthesis to make high-quality doped nanocrystals is provided. The first step includes synthesizing starting host particles. The second step includes dopant growth on the starting host particles. The third step includes final shell growth. In one embodiment, this method can be used to form Mn-doped CdS/ZnS core/shell nanocrystals. The Mn dopant can be formed inside the CdS core, at the core/shell interface, and/or in the ZnS shell. The subject method allows precisely controlling the impurity radial position and doping level in the nanocrystals.