Color Control of Pr³⁺ Luminescence by Electron–Hole Recombination Energy Transfer in CaTiO₃ and CaZrO₃

Abstract

Controlling luminescence in phosphors able to produce several emissions from different stable excited states determines their use in optical devices. We investigate the color control mechanism that quenches the greenish-blue emission in favor of the red one in the archetype phosphor CaTiO:Pr. State-of-the-art ab initio calculations indicate that direct host-to-dopant energy transfer (released by electron-hole recombination following the interband excitation and structural reorganization) selectively populates the D red luminescent state of Pr and bypasses the P greenish-blue emitter. Local defects can modulate the electron-hole recombination energy and therefore increase the red emission efficiency, as experimentally observed. The selection of red emission does not happen in CaZrO:Pr because the electron-hole recombination energy is much higher. The calculations could not support the widely accepted color control mechanism based on metal-to-metal charge transfer states. The conclusion sets new points of view for the color control of lanthanide activated inorganic phosphors.

Broadband infrared LEDs based on europium-to-terbium charge transfer luminescence

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Insights into the complexity of the excited states of Eu-doped luminescent materials

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Density Functional Characterization of the 4f‐Relevant Electronic Transitions of Lanthanide‐Doped Lu2O3 Luminescence Materials

“…In recent years, Seijo's group devoted to their study on 4 f –5 d transitions of Ce 3+ , Pr 3+ , Tb 3+ , Tm 2+ , Yb 2+ , etc. in garnets and revealed the color control mechanism of Pr 3+ in perovskites by means of state‐of‐the‐art ab initio methods of quantum chemistry. Besides, Lastusaari and co‐workers used DFT+ U to investigate Eu 2+ , La 3+ co‐doped Sr 2 MgSi 2 O 7 luminescence material.…”