The possibility of creating a lower junction of multijunction A3B5/Si solar cells based on an n-GaP/p-Si heterostructure was shown, using a combination of plasma enhanced atomic-layer deposition (PEALD) and metal-organic vapor phase epitaxy (MOVPE) at a temperature (Ts) not exceeding 650 °C. Photoelectric properties of structures grown at 650 °C, depends on the conditions of the PEALD process, in particular, the use of additional processing in Ar plasma.