Photoluminescence is important for solid-state lighting, sensors, and display devices. Among the materials exhibiting this property, doped phosphors are of particular interest owing to high thermal stability and potentially high quantum efficiency. Interestingly, the photoemission of such doped materials differs according to the oxidation states of their dopants. In this context, we carry out a soft chemistry route to reduce the dopants of inorganic phosphors by heating the solid-state compounds at low temperature with oxygen getters in glass tubes sealed under vacuum. This soft reduction enables to control the ratio Ni3+/Ni2+ in SrTiO3:Ni and Eu3+/Eu2+ in SrAl2O4:Eu or (CaMg)x(NaSc)1−xSi2O6:Eu. The optical properties could also be tuned according to these ratio. The control of the ratio Ni3+/Ni2+ in SrTiO3:Ni allowed the tuning of IR photoluminescence vs. optical absorption which could have potential applications in biomedicine. For SrAl2O4:Eu or (CaMg)x(NaSc)1−xSi2O6:Eu, the photoemission corresponding to the 4f-4f transition of Eu3+ dopant vs. the photoemission corresponding to the 4f-5d transition of Eu2+ dopant can be tuned to control the photoluminescence color of these compounds. In the specific case of (CaMg)x(NaSc)1−xSi2O6:Eu, the additional modification of the solid-solution composition enables to design a white phosphor for potential applications in solid-state lighting.

Tuning the photoluminescence by controlling the oxidation states of dopants

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.