Enhanced optical and luminescent properties of Cs4PbBr6@HNT/PMMA nanocomposites for photonic and display applications

Promising prospects for advanced optoelectronic applications are nanocomposites that combine enhanced luminous performance with high optical transparency. Using a solution casting process, Cs 4 PbBr 6 -decorated halloysite nanotubes (Cs 4 PbBr 6 @HNT) were successfully synthesized and evenly inserted into a poly(methyl methacrylate) (PMMA) matrix. Filler loadings of 0.0, 0.5, 1.0, and 2.0 wt% were used to create the final nanocomposites. X-ray diffraction analysis confirmed the formation of highly crystalline Cs 4 PbBr 6 with a rhombohedral phase. Fourier transform infrared spectroscopy (FTIR) revealed effective interaction between the PMMA matrix and the nanofillers, while scanning electron microscopy demonstrated uniform dispersion and improved surface morphology of the nanofillers within the polymer matrix. UV–Vis spectroscopy exhibited a characteristic absorption peak at 320 nm, and the optical bandgap decreased from 3.48 to 2.96 eV with increasing filler content. The optical parameters, including absorption coefficient, extinction coefficient, and refractive index, showed significant enhancement in the 270–285 nm region. Photoluminescence studies indicated that the 2 wt% nanocomposite exhibited the highest emission intensity and prolonged lifetime, attributed to delayed exciton recombination. Overall, the developed Cs 4 PbBr 6 @HNT/PMMA nanocomposites demonstrate improved optical stability, tunable bandgap, and enhanced luminescent performance, making them suitable for applications in light-emitting diodes, solid-state lasers, photodetectors, and UV-blocking devices.