Self‐Powered Luminescent Solar Concentrators‐Integrated Temperature Detection System with High Thermal Tolerance by Reversible Thermal Photoluminescence Luminophores

Abstract It is still a challenge to prepare the red‐emissive perovskite‐polymer composite with high photoluminescence quantum yield (PLQY) and reversible thermal photoluminescence (RTPL), which is key for improving the thermal tolerance of luminescent solar concentrators (LSCs). In this work, the red‐emissive (661 nm) CsPb(Br 0.25 I 0.75 ) 3 ‐PMMA composite with high PLQY of 85.96% and favorable RTPL below 160 °C is reported via a strategy of the defect passivation by halide ligand additives. The composite film possesses excellent long‐term stability in air, water, and high temperature environments. Then, a self‐powered temperature detection system, which consists of LSCs and a temperature detection module based on the RTPL composite film, is fabricated. On one hand, RTPL composite makes LSCs of superior thermal tolerance even after 100 cycles of temperature between room temperature and 160 °C. On the other hand, RTPL composite in the opaque box of the temperature detection module can give rise to the signal light without the interference of ambient light. As a result, the self‐powered temperature detection system achieves the quantitative temperature data display at different environment lights for 24 h in a day.