Doping is essential for controlling the optical and electronic properties of compound semiconductor nanocrystals. In solution-based synthesis, often doping efficiencies are low and dopants are excluded from the nanocrystals’ central cores. The research team developed a fundamentally different plasma-based process for synthesizing aluminum-doped zinc oxide nanocrystals. Due to the high chemical reactivities of the doping species in the plasma, dopants were incorporated irreversibly throughout nanocrystal growth, resulting in high doping efficiency and uniform dopant distribution.