A novel deep-red phosphor CaGdLiTeO6:Mn4+ with high color purity and quantum efficiency for plant cultivation applications

Photobiological studies have established that red light (600–750 nm) is essential for driving photosynthesis. However, many current Mn 4+ doped red phosphors are hindered by inherent limitations such as low quantum efficiency and inadequate moisture resistance, which restricts their practical application. In this study, we designed a novel phosphor, CaGdLiTeO 6 :Mn 4+ . Under 310 nm excitation, the phosphor exhibits the 2 E g → 4 A 2g transition of Mn 4+ , producing narrowband deep-red emission at 694 nm. Its emission spectrum significantly extends into the far-red region, effectively covering the absorption band of phytochrome Pfr (peak ∼730 nm). This material achieves an internal quantum efficiency (IQE) of 82.3 % and a color purity of 99.9 % (CIE coordinates: 0.7335, 0.2665), along with excellent thermal stability (67.64 % emission retention at 150 °C) and moisture resistance (96.56 % emission retention after 168 h immersion in water). Finally, a plant lighting system was developed based on this phosphor. In experiments, the height of wheatgrass increased by 31.1 %, while fresh weight and dry weight increased by 24.1 % and 30.3 %, respectively. This study provides new materials and strategies for the development of high-efficiency, eco-friendly agricultural light-emitting diodes. In addition, the prepared polymethylsiloxane composite films demonstrate their potential for flexible display and other applications under harsh environmental conditions.