This paper reviews recent results of the study of Zn diffusion from the vapor phase in important thermophotovoltaic (TPV) materials such as GaSb‐, InGaAsSb‐, InGaSb‐ and InAsSbP. Peculiarities of Zn diffusion in each of these materials and different ways of tailoring the Zn diffusion profile for fabrication of optimized emitters in TPV cells are discussed.