The effect of ethanol on structural, morphological and optical properties of Li(I) 8-hydroxyquinoline phosphor

The paper emphasized comparative investigation of Li(I) 8-hydroxyquinoline (Liq) phosphors which were prepared by acid base co-precipitation technique, with and without the presence of anhydrous 90% ethanol solution. Liq phosphor synthesized by using water solution shows blue emission, and it becomes prominent after recrystallized by anhydrous ethanol. The comparative analysis such as the formation of the compounds, phase purity and the existence of powder Liq in PMMA thin films was estimated by using X-ray diffraction study. The further confirmation of the formation of Liq powder, and further confirmed with Fourier transform infrared spectroscopy. The floppy agglomerated spherical grains turns to the micron size needle shape rods, indicating recrystallization of Liq phosphor by using anhydrous ethanol. The SEM micrographs envisioned their difference. The distribution of Liq powder in PMMA matrix was shown by phase image Atomic Force Microscopy (AFM). The optical property such as fluorescence of Liq powders and Liq:PMMA (01:10) thin films were estimated and compared. Both Liq powders exhibits broad band blue PL emission maximum at around 450 nm and it becomes more intense in the case of recrystallization by anhydrous ethanol. Moreover, a red shift (bathochromic shift) in the fluorescence emission was estimated from the Liq:PMMA blended thin films. The conclusive comparative study describes the improvement of phase purity, alteration of morphology and enhancement in the fluorescence intensity may be achieved by the recrystallization of Liq by anhydrous ethanol at the final phase of the synthesis.