Spectroscopic Studies of Strong Red Emitting CaAl2O4:Eu3+ Nano-phosphor for WLED’s Applications Using Judd–Ofelt Theory

Abstract

Eu3+ doped Calcium aluminate nanophosphor was fabricated via sonochemical route and characterized with scanning electron microscopy (SEM), X-ray diffraction (PXRD), photoluminescence (PL). PL excitation and emission spectrum were studied to explore the PL properties of CaAl2O4:Eu3+ nanophosphor. The PL emission spectrum exhibit intense peaks at ~ 577, 588, 615, 654 and 702 nm, which were assigned to transitions of Eu3+ ions as 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 respectively. The chromaticity coordinates of the synthesised sample was projected to be (0.608, 0.393) and its corresponding correlated color temperature (CCT) was estimated to be ∼ 1300 K, which is suitable for warm white light display applications. The Judd–Ofelt (J-O) intensity parameters and radiative charecteristics such as radiative lifetime, transition probabilities, branching ratios and lifetimes for the excited states of Eu3+ ions were computed from the emission spectra using Judd–Ofelt (J-O) theory. From aforementioned results, CaAl2O4:Eu3+ (5 mol %) nanophosphor can be regarded as a promising red phosphor, which is appropriate in solid state lighting and display devices using UV or blue chips