The role of Cr3+ and Cr4+ in emission brightness enhancement and sensitivity improvement of NIR-emitting Nd3+/Er3+ ratiometric luminescent thermometers

In this paper, co-doping with Cr 3+/4+ is proposed as a strategy to enhance the near-infrared luminescence emission of Nd 3+ /Er 3+ -based luminescence thermometers and modulate the temperature sensitivity of the ratio of Nd 3+ to Er 3+ in YAG.