Dependence of blue-emitting property on nanopore geometrical structure in Al-based porous anodic alumina membranes

Effects of ordering quality of the pores on the photoluminescence of porous anodic alumina prepared in oxalic acid

“…The optical properties of PAA have been known to change with anodizing conditions (electrolyte and voltage) [27,31,32]. The present work demonstrates that the PLE strongly depends on the quality of ordering at a given anodizing voltage.…”

The effect of high‐temperature annealing on optical properties of porous anodic alumina formed in oxalic acid

“…It has also been reported that a large number of F centres exist and that the PL peak is located at 2.9 eV (430 nm) in crystalline alumina (18). Huang et al (11,17) think that two luminescent bands of AAMs arise from two kinds of different defects (F and F + centres) prepared in C 2 H 2 O 4 . The F centres have a lower absorption band than the F + centres in crystalline sapphire (19).…”

“…Oxygen ions transform from OH − in the electrolyte and migrate through the barrier layer under a high electric field (about 10 −7 V/cm) by a vacancy mechanism (11); this implies that many oxygen vacancies exist in the AAMs. The F and F + centres are produced from partial oxygen vacancies remaining in the formed AAM membrane (11). The presence of oxygen vacancies has generally been considered to be responsible for the PL of anodic alumina (8, 9).…”

“…Xu et al (10) suggest that the blue emission band in AAMs originates from the co-actions of the singly ionized oxygen vacancies and the luminescent centres transformed from oxalic impurities. Huang et al (11) consider that two luminescent bands of AAMs arise from two different kinds of defect (F and F + centres) prepared in C 2 H 2 O 4 . In this study we investigated the PL properties of AAMs formed in oxalic acid.…”

Quantitative analysis of morphological and photoluminescence properties of porous anodic alumina formed in sulfuric acid

“…The interests for this topic are mainly focused on the relationship of photoluminescence (PL) properties with the alumina and the mechanism evolving the light emission [11]. Table 1 shows a summary of the PL emission bands of as-prepared PAA generated under different anodization conditions from the literature [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. From the table, it is clear that most of the PL studies on PAA were anodized using oxalic acid because it demonstrates higher intensities of PL bands due to weaker oxidation activity and resulting in more oxygen vacancies [12].…”