Origin of bimodal luminescence in Cs4PbBr6 quantum dots glass ceramic

Abstract

Abstract For a nanometre spherical particle, when the radius is smaller than Bohr radius, quantum confinement effect (QCE) will predominate and a series of interesting luminescence phenomena can be obtained. In this work, blue-green tuneable bimodal luminescence in rare earth (RE) ions doped Cs4PbBr6 quantum dots (QDs) tellurite glass can be achieved due to QCE. The study of luminescence mechanism indicates that the blue luminescence originates from exciton energy level and the green luminescence originates from intrinsic energy level of Cs4PbBr6. The prepared QDs glass ceramic exhibits superior water stability in which the photoluminescence (PL) intensity remains 131.3% after immersed in water for 60 days. A waterproof ink based on QDs glass ceramic power/epoxy silicone is fabricated, which exhibits good water stability and luminescence properties. This work puts forward an interesting blue-green tunable bimodal luminescence phenomenon of Cs4PbBr6 QDs glass ceramic, and the luminescence mechanism has been illustrated clearly, which has significantly instructive value to related work.