In this work, we studied the influence of GaP compensating layers on the characteristics of GaAs solar cells with InGaAs quantum dot arrays. An increase in the overall level of quantum efficiency in the absorption range of quantum  dots (870–1000 nm) by more than 10% has been demonstrated when GaP layers are embedded in GaAs intermediate layer (spacer) of a quantum dot array. It was also shown that in this case a noticeable increase in the open-circuit voltage can be achieved at high solar concentration.