Spectroscopic study of white light modulation in SrAl2O4:Eu2+, Dy3+- ZnGa2O4:Cr3+ composite

The present study reports a highly efficient SrAl2O4:Eu-2(+), Dy-3(+) and ZnGa2O4:Cr-3(+) phosphor-composite facilitating flicker-controlled broadband white light emission for AC-driven lighting applications. The XRD analysis reveals the successful formation of the composite, whereas, the EDS analysis indicates that the samples are free from any external impurity. The emission investigation for the prepared composite was performed under Xe-lamp, LED, and laser spectroscopy. The emission outcomes reflect that both the green-emitting Eu-2(+) ions (520 nm), afterglow > 5 hours, and red emitting Cr-3(+) (695 nm) are efficiently excitable by blue LEDs. A precise color tunability was achieved under dual laser excitations of 405 nm and 450 nm. The 450 nm-modified system demonstrated remarkable chromatic accuracy, achieving CRI of 92 and R9 value of 80, with CIE coordinate (0.337, 0.379). Interestingly, under 405 nm LED illumination, the emission properties were further refined, yielding CRI of 93, R9 of 92, and CIE coordinates (0.311, 0.346). In addition to that, the AC lighting flickering was mitigated from 99.9 % to approximately similar to 51 %, representing a transformative advancement in the development of stable, high-quality AC lighting technologies.