In this work, TlIn[Formula: see text]Ga[Formula: see text]Se2 single crystals were grown by zone recrystallization methods and their X-ray phase analysis was performed. The lattice parameters were determined and it was found that crystals based on the original TlIn[Formula: see text]Ga[Formula: see text]Se2 compound crystallized in the same tetragonal symmetry, the space group [Formula: see text]. It was revealed that with partial substitution of indium atoms by gallium atoms in the TlIn[Formula: see text]Ga[Formula: see text]Se2 lattice, the parameters of unit cells change according to the additivity law. First time it was found that with the simultaneous influence of electromagnetic and sound waves, an electromotive force (e.m.f.) occurs or short circuit current. The studies were carried out in the frequency range of electromagnetic radiation of 50–143 kHz. It was revealed that when the investigated crystals were irradiated with magnetic radiation in the absence of sound waves, there was no e.m.f. on the electrodes as well as memory when exposed only to sound. Based on the existing theoretical information, the nature of the revealed single crystal of the acousto-photovoltaic effect was explained.