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

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 ZnGa2O4: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.

Ytterbium-Doped CsPbCl3 Quantum Cutters for Near-Infrared Light-Emitting Diodes

“…At present, Cr 3+ -doped inorganic phosphors have been regarded as desirable NIR emitters, which can yield either narrowband (sharp-line) or broadband NIR emission depending on the doping hosts . Although great progress has been made in this field, most reported Cr 3+ emissions with high photoluminescence quantum yields (PLQYs) are actually located in the far-red region visible to the naked eyes (the central wavelengths of 700–800 nm) − rather than the NIR one (especially for emission wavelengths over 900 nm), which remarkably limits their practical applications.…”

Hidden Structural Evolution and Bond Valence Control in Near-Infrared Phosphors for Light-Emitting Diodes

“…Infrared (IR) luminescent materials have elicited considerable attention and have been utilized in biomolecular imaging, biomodulation, food analysis, and plant cultivation. − Recently, phosphor-converted IR light-emitting diodes (pc-IR LEDs) have evolved into smart devices with the advantages of high output power, high efficiency, and small size. − Therefore, IR phosphor materials are crucial components of these devices, affecting the overall performance of the resulting spectrum. Cr 3+ , as a unique and ideal near-IR (NIR) emitter that can produce either sharp-line or broadband spectra, has become a promising candidate for producing IR light.…”

Surface-Protected High-Efficiency Nanophosphors via Space-Limited Ship-in-a-Bottle Synthesis for Broadband Near-Infrared Mini-Light-Emitting Diodes

“…Consequently, the IQE of the GOC@MSN is measured and compared with those of other nanosized phosphors, as shown in Figure a. The GOC@MSN is provided with a high IQE of 91.4%, which is considerably higher than those of ZnGa 2 O 4 :Cr 3+ , Sn 4+ @MSN, NaCeF 4 :Er 3+ /Yb 3+ , CaF 2 :Ce 3+ /Mn 2+ , and CaF 2 :Ce 3+ /Tb 3+ /Na + . − The IQE value of the GOC@MSN is even comparable with that of the bulk Ga 2 O 3 :Cr 3+ phosphor (92.4%) . To elucidate this high IQE value, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images are measured for the MSN and GOC@MSN, as shown in panels b and c of Figure .…”