Morphology and photoluminescence of nano-porous anodic alumina membranes obtained in oxalic acid at different anodization potentials

Abstract

Porous Anodic alumina (PAA) with highly ordered pore geometry serves as an ideal template for future development of nanodevices. In the present work, PAA was prepared by varying anodization potential from 10 to 50 V in oxalic acid at 8°C with a constant electrolyte concentration of 0.3 M. The influence of anodization potential on the structural and photoluminescence (PL) properties of PAA has been studied. The effect of anodization potential on the main pore characteristics of PAA such as pore diameter, interpore distance, pore density, porosity and circularity was studied. It was observed that circularity of PAA was nearly equal to one in the case of anodization potential of 40 V. Highest regularity ratio (RR) obtained for PAA formed in 40 V and it was calculated by WSxM software. It was noticed that with increasing anodization potential there is a slight change in PL spectra of PAA and shows a strong PL peak in blue region.

Optical Characterization of ALD-Coated Nanoporous Alumina Structures: Effect of Sample Geometry or Coated Layer Material

“…As it was already indicated, a particular property of nanoporous alumina structures (NPASs) obtained by the electrochemical anodization method is photoluminescence (PL), As it was already indicated, a particular property of nanoporous alumina structures (NPASs) obtained by the electrochemical anodization method is photoluminescence (PL), which was initially reported in the 1980s and is ascribed to structural defects, namely oxygen vacancies, present in NPASs as a consequence of the incorporation of impurities during the anodic oxidation process [35]. Since PL can be of interest for different applications, a number of papers correlating PL spectra with sample fabrication parameters (mainly anodization voltage but also electrolyte solutions and electrolyte mixtures or temperature, which affects sample nanometric geometry) or even aluminum purity have been reported lately [67][68][69][70][71]. These results show PL curves with similar shapes and maximum intensity wavelengths ranging between 420 nm and 460 nm, depending on anodization voltage values using oxalic acid as the electrolyte (for excitation wavelengths around 330 nm).…”

“…Micromachines 2023, 14, x FOR PEER REVIEW 10 of 14 during the anodic oxidation process [35]. Since PL can be of interest for different applications, a number of papers correlating PL spectra with sample fabrication parameters (mainly anodization voltage but also electrolyte solutions and electrolyte mixtures or temperature, which affects sample nanometric geometry) or even aluminum purity have been reported lately [67][68][69][70][71]. These results show PL curves with similar shapes and maximum intensity wavelengths ranging between 420 nm and 460 nm, depending on anodization voltage values using oxalic acid as the electrolyte (for excitation wavelengths around 330 nm).…”

Review—The Variation of Anodization Conditions and the Structural Properties of Nanoporous Anodic Alumina (NAA) within Different Acidic Solutions

“…The temperature of oxalic acid could improve the regularity of NAA structure, but high temperatures (313 K) may lead to pore collapse. 51 Ramana et al 52 studied the highly ordered NAA structure by the anodizing process in 0.3 M oxalic acid at 281 K from 10 V to 50 V. This study includes the relationship between the anodization potential, and photoluminescence (PL) properties of NAA. They reported the effect of pore diameter, interpore distance, porosity and circularity of NAA by the variation of anodization potential.…”