Photoluminescence of perovskite-type Cr<sup>3+</sup>-activated phosphors in the La–Al–Ti–O system

Cr 3+ -activated near-infrared emitting phosphor has a potential application in plant growth and sensing 10 technologies.Herein, we synthesized near-infrared emitting La 1-x/3 Al 1-x-y Ti x O 3 : yCr 3+ phosphor by a solid-state 11 reaction.La 1-x/3 Al 1-x-y Ti x O 3 : yCr 3+ (x = 0.2, y = 0.003) showed the near-infrared emission at 751 nm with a full width 12 at half-maximum of 41 nm under 351 nm excitation.The internal and external quantum efficiencies were 54.4% 13 and 25.5%, respectively.The luminescence intensities at 150 of the La 1-x/3 Al 1-x-y Ti x O 3 : yCr 3+ (x = 0.1, 0.2, and 0.3, 14 y = 0.003) were 32%, 17%, and 3% of those at room temperature, respectively.The thermal quenching effect 15 strongly occurred with increasing the amount of Ti and it was related to the change in the absorbance edge of the 16 host material La 1-x/3 Al 1-x-y Ti x O 3 .17