Tb3+-doped yttrium garnets: Promising tunable green phosphors for solid-state lighting

Luminescent Tb3+ yttrium-based garnets powders have been prepared by the sol–gel route. Optical properties of samples have been studied. Excitation spectra have revealed several excitation bands between 200 and 500 nm, which match very well with newly developed AlGaN-based deep-ultraviolet (DUV) or near-UV LEDs. Excitation profiles are dependent on the matrix formula. Emission spectral features studied upon different UV excitation wavelength have revealed that luminescence efficiency can be significantly improved by tuning the matrix composition. Thus, optical properties can be tuned to optimize the lighting source features, according to the kind of UV LEDs employed.