Аннотация:Porous anodic aluminum oxide (PAAO) due to its accessible manufacturing technology andunique physical and chemical properties has found wide application in various fields of science and technology.The PAAO is formed in sulfuric acid and consists of ordered arrays of pores with an average diameter inthe range 10–15 nm. However, for samples synthesized at the electrolyte temperature of 40°C, the surfacebecomes disordered and consists of individual thread-like fibers. For the first time, paramagnetic centers(defects) were identified and their influence on PL of analyte (Rhodamine B) was studied in a series of samplesobtained in a wide temperature range: 5–40°C. It was established that in PAAO formed at 5°C oxygenvacancies (F+ centers) are detected. In samples synthesized at higher temperatures Al–SO4 paramagneticcomplexes are additionally observed, the maximum concentration of which is achieved in samples obtainedat an electrolyte temperature of 25°C and is more than an order of magnitude higher than the concentrationof F+ centers. The minimum PL intensity of the Rhodamine B was found in samples with the highest concentrationof paramagnetic centers. This effect is due to the fact that part of the exciting radiation is absorbedby paramagnetic centers (Al–SO4 and F+), therefore the PL of the dye decreases. Therefore, it is possible tocontrol the type, concentration of paramagnetic centers in PAAO and the intensity of photoluminescence ofthe dye in its pores by varying the temperature of the electrolyte and dye concentration. The obtained resultsmay be useful in the development of PAAO-based optical sensor platforms.
