Surface Plasmon Resonance and Luminescence of Bis(2-Methyl-8-Hydroxyquinoline)-Aluminum Nanoparticles: A Photophysical Perspective
摘要
Bis(2-methyl-8-hydroxyquinoline)-aluminum [Al(MQ)2] nanoparticles were synthesized using a chemical precipitation method, and their photophysical properties, which apply to display materials, have been studied. Powder X-ray diffraction was used to confirm the presence of a nanocrystalline phase with a mean size of 17.28 nm, and scanning electron microscopy revealed cylindrical aggregates with diameters ranging from 10 to 30 nm. The FTIR study was utilized to identify the functional groups, while EDX elemental analysis validated the chemical composition of the Al(MQ)2 sample. Optical absorbance studies revealed high optical transparency in the visible and near-infrared wavelengths, with a UV absorbance band at 308 nm due to surface plasmon resonance. A direct optical bandgap of 3.45 eV was deduced, and the Urbach energy was measured to be 0.19 eV, reflecting a sharp absorption edge and low structural disorder. The photoluminescence analysis revealed the presence of a strong green emission at 502 nm with 71% color purity, as depicted in the CIE chromaticity diagram; consequently, the Al(MQ)2 nanoparticles are suitable for use as emissive materials. Thermal analysis (TG/DTG and DSC) demonstrated that Al(MQ)2 does not significantly decompose at temperatures up to 278 °C, further indicating its utility. The unique combination of the structural, distinct SPR feature with efficient luminescence implies that Al(MQ)2 nanoparticles may be well suited for applications in plasmon-enhanced light-harvesting, sensing, and emissive displays.