The effect of doping with holmium (Ho) and erbium (Er) rare-earth elements (REE) on the main parameters and characteristics of photocells based on p-GaSe/n-InSe heterostructures has been experimentally studied. Photo-electromotive force measurements were performed for undoped and rare-earth doped samples and obtained results comparatively analyzed. The light characteristic of the samples shows that significant improvement are observed in the rare-earth doped crystals. The possibility of targeted control, as well as increasing their reproducibility and stability by changing the content of the introduced impurity ([Formula: see text]), is shown. The optimal situation is provided by alloying Er with [Formula: see text] at.%.