Fangrui Cheng*, Luxia Zhong, Yifei Zhao, Yizhi Zheng, Yixuan Lai, Chengjie Li, Fangmin Lin, Runying Zheng, Ruirui Yang, Xianjiao Ou, Hang Zhu, Renping Cao*, Shi Ye*

Cite this article: https://doi.org/10.1016/j.cjsc.2026.101036

Publication date:

Keywords: Cr³⁺ ion; Garnet structure; NIR; Anti-quenching mechanism; Optoelectronic applications

ABSTRACT

The inorganic oxide near-infrared (NIR) phosphor-polydimethylsiloxane (PDMS) composite material integrates excellent optical properties of inorganic oxides with flexibility and moisture resistance of PDMS matrix, offering a promising platform for applications in cutting edge flexible optoelectronics. The high performance Lu2SrAl4SiO12: Cr3+ (LSASO: Cr) phosphors and their flexible composite films were successfully developed. Notably, the LSASO: 0.05Cr3+ phosphor exhibits ultra-high thermal stability of 144%, and its flexible composite film derived from it also demonstrate thermal stability of 142%. These are all attributed to a five fold synergistic anti-quenching mechanism: wide bandgap engineering, weak electron-phonon coupling, defect trap regulation, high structural rigidity, and optimized electron distribution. The phosphor exhibits exceptional internal quantum efficiency (IQE) of 90% and external quantum efficiency (EQE) of 43%, while the packaged NIR pc-LEDs also demonstrate super photoelectric conversion efficiency (18%). The phosphor-PDMS composite films enable diverse optoelectronic applications, having been successfully applied to high sensitivity non-contact temperature sensing (Sr = 1.73% K−1 at 498 K, FIR reproducibility > 90%), plant growth promotion (23% increase in lettuce biomass), and high-power night vision lighting systems. This work provides novel insights into the design of heat quenching resistant NIR materials and the multifunctional optoelectronic applications of their PDMS composite films.