The Cu₂GeSe₃ compound and phases based on it are of interest as environmentally friendly thermoelectric and photovoltaic materials. This paper presents the results of a thermodynamic study of this compound by the method of electromotive forces. We measured the EMF of concentration cells concerning copper electrode with solid Cu⁺ conductive electrolyte Cu₄RbCl₃I₂ in the 300-450 K temperature range. Based on the obtained experimental data, the partial molar functions of copper in equilibrium alloys from the three-phase region of the Cu₂GeSe₃ -GeSe₂-Se phase diagram, as well as the standard thermodynamic functions of formation and the standard entropy of the Cu₂GeSe₃ compound, are calculated. A comparative analysis of the obtained results with the available literature data was carried out

doi.org/10.32737/0005-2531-2023-1-108-114