Positive luminescence thermal coefficient of Mn2+ions for highly sensitive luminescence thermometry

Luminescence thermal quenching phenomenon is a major limitation in the development of luminescent ther-mometers of high-resolution operating in the temperature range above 400 K. Therefore, in order to circumvent this limitation, in this work CaGa4O7:0.01 % Mn2+, 0.05 % Cr3+ is proposed as a new biocompatible ther-mometer in which the luminescence intensity of the Mn2+-based emission is thermally enhanced providing a high signal-to-noise ratio at temperatures even above 520 K. Therefore, as shown, the intensity ratio of Mn2+ and Cr3+ ions can be successfully used for ratiometric temperature readout not only for thermal sensing with a relative sensitivity of 2.08 % K-1 at 403 K and delta T = 0.1 K and for 2-dimensional thermal imaging using a digital camera.

Automated summary

A new biocompatible thermometer CaGa4O7:0.01 % Mn2+, 0.05 % Cr3+ is proposed in this study to overcome the limitation of luminescence thermal quenching in high-resolution luminescent thermometers above 400 K. The thermal enhancement of Mn2+-based emission enables a high signal-to-noise ratio at temperatures above 520 K, making it suitable for ratiometric temperature readout and thermal imaging.