Band-gap engineering in Lu3Al5O12:Pr by Sc3+ or In3+ substitution

Pr3+-doped Lu3−xScxAl5O12 and Lu3−xInxAl5O12 (x=0, 0.025, 0.1, 0.25, 0.5, 0.75, 1, and 2) polycrystals are fabricated by the high-temperature solid state reaction method. Although X-ray excited luminescence measurements show that there is no positive contribution of Sc3+ or In3+ substitution on the scintillation efficiency, but the physical aspects of band-gap engineering such as the cooperative process of excitation and thermal ionization of 5d1 excited state are illustrated in this study. We employ a combination of optical diffuse reflectance, photoluminescence, decay kinetic, thermoluminescence experiments to reveal the influence of Sc3+ or In3+ substitution on electronic structure and luminescent properties in Pr3+-doped lutetium aluminate garnet.