While Quantum Dots (QDs) have found commercial success in display applications, there are currently no widely available solid state lighting products making use of QD nanotechnology. In order to have real-world success in today’s lighting market, QDs must be capable of being placed in on-chip configurations, as remote phosphor configurations are typically much more expensive. Here we demonstrate solid-state lighting devices made with on-chip QDs. These devices show robust reliability under both dry and wet high stress conditions. High color quality lighting metrics can easily be achieved using these narrow, tunable QD downconverters: CRI values of Ra
> 90 as well as R9 values > 80 are readily available when combining QDs with green phosphors. Furthermore, we show that QDs afford a 15% increase in overall efficiency compared to traditional phosphor downconverted SSL devices. The fundamental limit of QD linewidth is examined through single particle QD emission studies. Using standard Cd-based QD synthesis, it is found that single particle linewidths of 20 nm FWHM represent a lower limit to the narrowness of QD emission in the near term.
Quantum dots (QDs) are rare-earth free downconverters which have been demonstrated as ideal phosphor replacement materials from an optical perspective, with the potential to enable a 30% or larger improvement in LED efficiency as compared to today’s rare-earth phosphors at the same quality of light (higher CRI implementations see larger improvements). However to date QDs have demonstrated less than ideal reliability under standard LED chip conditions, prohibiting cost-effective integration into conventional luminaire formats. This talk will discuss the present status and future prospects of QDs as LED downconverters, including recent advances in connecting quantum dot structure to high temperature and high intensity performance, an updated look at QD reliability, and the limits of QDs in a variety of phosphor configurations.
Conference Committee Involvement (1)
Light-Emitting Devices, Materials, and Applications
4 February 2019 | San Francisco, California, United States