Comparative experimental data, using dynamic light scattering methods, scanning electron and atomic force microscopy, on the composition, crystal structure, semiconductor and photoelectric properties of PbSe films deposited at the presence of sodium sulfite Na_2SO_3 and “sodium sulfite–ascorbic acid” complex antioxidant additive are presented. Significant changes in morphology, elemental and phase composition, the period of the crystal lattice of PbSe films been synthesized in the presence of Na_2SO_3 and Na_2SO_3 + C_6H_8O_6 anti-oxidants before and after their thermoactivation at 653 K are found. It is shown that the introduction of a complex additive in comparison with Na_2SO_3 increases the homogeneity of the particles forming the layer, decreases the microstresses in it, reduces the value of thermal band gap from 0.349 to 0.308 eV, and increases the volt-watt sensitivity of the films by 28–30%.