Employing high efficiency Gd3Ga2Al3O12:Cr3+ phosphor glass films to enhance the long-term operating stability of high-power LED plant lighting device

Near-infrared (NIR) light is extensively utilized in plant lighting due to its ability to promote plant growth and increase photosynthesis efficiency. To optimize crop yield and morphology, developing a NIR lighting source with high efficiency and long-term operating stability is essential. However, it's still a formidable challenge. Herein, we have prepared a Gd 3 Ga 2 Al 3 O 12 :Cr 3+ phosphor glass films on sapphire (GGAG-PGF) with external quantum efficiency up to 40 %, as well as excellent thermal stability (96.7 %@150 °C of the initial integrated intensity at 25 °C). When the drive voltage and current are 21 V and 240 mA, the surface working temperature of the prepared GGAG-PGF based LED device is 117.2 °C, showing a 29 % drop compared with that the conventional pc-LED (164.9 °C). Moreover, it gives an excellent long-term operating stability after 21 days of continuous high-power working. Benefitting from the suitable spectral profile and excellent luminescence performance of GGAG-PGF, the potential application in plant lighting is evaluated through supplementing the NIR lighting for Italian lettuce with the as-fabricated GGAG-PGF based LED. The results demonstrated it can effectively regulate plant biomass with an increase of 26.8 % in fresh weight and 30 % in dry weight.