Ramana Reddy, P.Ajith, K.M.Udayashankar, N.K.2026-02-052020Materials Science in Semiconductor Processing, 2020, 106, , pp. -13698001https://doi.org/10.1016/j.mssp.2019.104755https://idr.nitk.ac.in/handle/123456789/24078The free-standing porous anodic alumina membranes (AAM) were prepared in oxalic acid by varying electrolyte concentration from 0.1 to 0.9 M with a constant potential of 40 V at 8 °C. The influence of electrolyte concentration on the morphological and optical features of AAM has been studied. Regularity ratio (RR) of AAM was measured using WSxM software, highest RR obtained for AAM formed in 0.3 M. From X-ray diffraction (XRD) analysis, it was found that prepared AAM were amorphous in nature. UV–Vis absorbance spectra reveal that absorbance bands slightly moves towards the higher wavelength side with increasing electrolyte concentration. Photoluminescence (PL) of AAM has been studied and related with RR of AAM. PL measurements of AAM exhibit strong PL peak in blue region, having a slight change with increasing electrolyte concentration. PL bands were originating from two kinds of oxygen-deficient defects (F and F+), their distributions were discussed on the basis of PL spectrum. © 2019 Elsevier LtdAluminaAluminum oxideAluminum sheetOxalic acidPhotoluminescenceX ray diffraction analysisAbsorbance spectrumAnodizationsElectrolyte concentrationOxygen-deficient defectsPhotoluminescence propertiesPorous anodic aluminaPorous anodic alumina membranesRegularity ratioElectrolytes