Methods of fabricating semiconductor p-n junctions and semiconductor devices containing p-n junctions are disclosed in which the p-n junctions contain concentration profiles for the p-type and n-type dopants that are controllable and independent of a dopant diffusion profile. The p-n junction is disposed between a layer of semiconductor doped with a p-type dopant and a layer of semiconductor doped with an n-type dopant. The p-n junction is fabricated using a crystal growth process that allows dynamic control and variation of both p-type and n-type dopant concentrations during the crystal growth process.