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Phosphor materials with narrow emission bands and high quantum efficiency have received a good amount of attention, suggesting the possibility of several applications in the field of optoelectronic devices. SrTiO 3 :Pr is an example of a material with these characteristics. In this study, mesocrystal samples of Sr 0.998 Pr 0.002 Ti 1−y Al y O 3 (SrTiO 3 :Pr,Al) were prepared via a hydrothermal route, and the morphology presented a microcube shape and pristine structure with Pm3m space group without any spurious phases for all Al concentrations. Measurements of X-ray absorption spectroscopy (XAS) at Ti K-, L II , III -, and O K-edges, calculated projected density of states, and Raman spectroscopy revealed that the hydrothermal method and Al incorporation cause a local symmetry breaking, deviating from the cubic structure, Ti off-center displacement, tilting of TiO 6 octahedra, and O vacancies. As the Al content increases, the intensity of some emissions in the photoluminescence spectra also increases up to 3 at%. The disorder produced by Al concentration leads to a lower symmetry around Pr3+ sites, resulting in an increase in the probabilities of transitions for Pr3+ ions due to the mixing of the opposite parity in 4 f configurational levels. On the other hand, higher Al concentrations cause a decrease in the intensity of Pr emissions, which is related to their quenching because of O vacancies. Additionally, intrinsic defects due to the hydrothermal route and Al incorporation generate a broad emission in the photoluminescence spectra. This broad emission is associated with intermediary electronic levels in the band gap caused by these intrinsic defects. • Sr 0.998 Pr 0.002 Ti 1−y Al y O 3 phosphor mesocrystals were prepared via hydrothermal route. • The morphology presents microcube shape of the mesocrystals without spurious phases. • X-ray absorption spectroscopy detected local disorder and O vacancies. • Lower symmetry around Pr3+ increases the probabilities of the 4f transitions. • Intrinsic defects generate a broad emission in photoluminescence spectra. [ABSTRACT FROM AUTHOR]