Luminescence improvement of Gd3Ga5O12:Cr3+,Bi3+ NIR phosphor with superior thermal stability for plant cultivation

Near infrared (NIR) phosphor has continued booming in plant cultivation due to the excellent match with the phytochrome PFR and PR. Herein, the garnet NIR phosphor Gd3Ga5O12:Cr3+ is prepared and energy transfer engineering is created by co-doping with Bi3+. Enhanced luminescence improvement is observed in the Bi3+ co-doped samples and the energy transfer between Bi3+ and Cr3+ is confirmed. Optimized Gd2.96Bi0.04Ga4.96Cr0.04O12 exhibits abnormal thermal quenching behaviour and the integral emission intensity reaches 102% of that at room temperature. The relative sensitivity Sr and absolute sensitivity Sa were estimated to be 0.19% K-1 and 0.252 K-1, respectively. This garnet NIR phosphor is coated to the blue chip to fabricate the NIR light emitting diodes for dragon fruit tree cultivation as light compensation during the night. The spectrum of the device covers well of all the absorption spectra of chlorophyll B and phytochrome PFR, exhibiting huge application of this garnet NIR phosphor in plant cultivation.