Journal
ACS PHOTONICS
Volume 8, Issue 6, Pages 1784-1793Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsphotonics.1c00372
Keywords
phosphors; saturation; droop; LEDs; lanthanides; Mn4+ luminescence; spectroscopy
Categories
Funding
- Dutch Research Council (NWO) [731.017.401]
- NWO Veni Grant [722.017.002]
- Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC), an NWO Gravitation program - Ministry of Education, Culture and Science of the Government of The Netherlands
Ask authors/readers for more resources
Commercial lighting with LED phosphor materials based on blue light-emitting diodes may saturate in high-power applications, leading to decreased light output. By investigating the saturation mechanisms through experiments and modeling, strategies to improve performance and efficiency can be developed.
Commercial lighting for ambient and display applications is mostly based on blue light-emitting diodes (LEDs) combined with phosphor materials that convert some of the blue light into green, yellow, orange, and red. Not many phosphor materials can offer stable output under high incident light intensities for thousands of operating hours. Even the most promising LED phosphors saturate in high-power applications, that is, they show decreased light output. The saturation behavior is often poorly understood. Here, we review three popular commercial LED phosphor materials, Y3Al5O12 doped with Ce3+, CaAlSiN3 doped with Eu2+, and K2SiF6 doped with Mn4+, and unravel their saturation mechanisms. Experiments with square-wave-modulated laser excitation reveal the dynamics of absorption and decay of the luminescent centers. By modeling these dynamics and linking them to the saturation of the phosphor output intensity, we distinguish saturation by ground-state depletion, thermal quenching, and ionization of the centers. We discuss the implications of each of these processes for LED applications. Understanding the saturation mechanisms of popular LED phosphors could lead to strategies to improve their performance and efficiency or guide the development of new materials.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available