Broadband Cr3+ , Sn4+ -Doped Oxide Nanophosphors for Infrared Mini Light-Emitting Diodes

Angew Chem Int Ed Engl. 2019 Feb 11;58(7):2069-2072. doi: 10.1002/anie.201813340. Epub 2019 Jan 18.

Abstract

Light-emitting diodes break barriers of size and performance for displays. With devices becoming smaller, the materials also need to get smaller. Chromium(III)-doped oxide phosphors, which emit near-infrared (NIR) light, have recently been used in small electronic devices. In this work, mesoporous silica nanoparticles were used as nanocarriers. The nanophosphor ZnGa2 O4 :Cr3+ ,Sn4+ formed in the mesopore after sintering. Good dispersity and morphology were performed with average diameters of 71±7 nm. It emitted light at 600-850 nm; the intensity was optimized by tuning the doping ratio of Cr3+ and Sn4+ . Meanwhile, the light conversion efficiency increased from 7.8 % to 37 % and the molar concentration increased from 0.125 m to 0.5 m. The higher radiant flux of 3.3 mW was obtained by operating an input current of 45 mA. However, the NIR nanophosphor showed good performance on mini light-emitting diode chips.

Keywords: light emitting diodes; mesoporous structures; nanophosphors; near infrared; silica nanoparticles.