The effect of modifying the composition of a glass matrix based on the Ga2S3-GeS2:Pr3+ system due to the addition of La2S3 on the structure and the optical and luminescent properties of these glasses has been studied. It has been shown that the addition of La2S3 leads to changes in the nearest structural environment of Ga, Ge, and S and increases the degree of ionicity of the bonds of the Pr3+ ion. Despite the existence of a large glass formation region in the Ga2S3-GeS2-La2S3 system and the structural and chemical similarity of La and Pr, La2S3 does not promote a more uniform distribution of Pr3+ ions in the glass matrix, and thus does not reduce the concentration quenching of the luminescence of Pr3+ ions. However, the addition of La2S3 increases the probability of emission of Pr3+ ions and decreases the radiative lifetime. Additionally, it was shown that, when studying the structure and luminescent properties of glasses with La, it is necessary to take into account a significant concentration of rare earth traces (Pr and Nd).
Keywords: IR materials; chalcogenide glasses; luminescent materials.