Modifying the Electronic Trap Distribution in Ba2Zr2Si3O12: Eu2+, Nd3+ via Regulating the Composition of Matrix Elements

The appropriate electronic traps and energy gap between the bottom of the conduction band (CB) and the excited state of the luminescence center are crucial factors for excellent persistent luminescence (PersL) performance. In this paper, the possibilities of regulating electronic traps and the energy gap mentioned above are investigated via partial substitution of the host lattice cation Zr4+ by Hf4+. A comprehensive study on the structural transformation, luminescent properties and PersL decay curves were carried out to unearth the influence of partially substituting Zr4+ ions by Hf4+ ions. The broader band gap was revealed by diffuse reflectance (DR) spectra and Density functional theory (DFT) calculations, which ascribed to the relatively higher energy levels of Hf 5d state compared with Zr 4d state. Whereas, the thermoluminescence (TL) spectra show a successive red-shift due to the broader band gap and the deeper trap depth from the bottom of the CB to the trap energy levels. Guided by regulating the ...