True Yellow Light-Emitting Diodes as Phosphor for Tunable Color-Rendering Index Laser-Based White Light
Ng, Tien Khee
Consiglio, Giuseppe Bernardo
Elafandy, Rami T.
Anjum, Dalaver H.
Alhamoud, Abdullah A.
Alatawi, Abdullah A.
Alyamani, Ahmed Y.
El-Desouki, Munir M.
Ooi, Boon S.
KAUST DepartmentImaging and Characterization Core Lab
KAUST Grant NumberBAS/1/1614-01-01
Permanent link to this recordhttp://hdl.handle.net/10754/622490
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AbstractAn urgent challenge for the lighting research community is the lack of efficient optical devices emitting in between 500 and 600 nm, resulting in the “green-yellow gap”. In particular, true green (∼555 nm) and true yellow (∼590 nm), along with blue and red, constitute four technologically important colors. The III-nitride material system, being the most promising choice of platform to bridge this gap, still suffers from high dislocation density and poor crystal quality in realizing high-power, efficient devices. Particularly, the high polarization fields in the active region of such 2D quantum confined structures prevent efficient recombination of carriers. Here we demonstrate a true yellow nanowire (NW) light emitting diode (LED) with peak emission of 588 nm at 29.5 A/cm2 (75 mA in a 0.5 × 0.5 mm2 device) and a low turn-on voltage of ∼2.5 V, while having an internal quantum efficiency of 39%, and without “efficiency droop” up to an injection current density of 29.5 A/cm2. By mixing yellow light from a NW LED in reflective configuration with that of a red, green, and blue laser diode (LD), white light with a correlated color temperature of ∼6000 K and color-rendering index of 87.7 was achieved. The nitride-NW-based device offers a robust, long-term stability for realizing yellow light emitters for tunable color-rendering index solid-state lighting, on a scalable, low-cost, foundry-compatible titanium/silicon substrate, suitable for industry uptake.
CitationJanjua B, Ng TK, Zhao C, Prabaswara A, Consiglio GB, et al. (2016) True Yellow Light-Emitting Diodes as Phosphor for Tunable Color-Rendering Index Laser-Based White Light. ACS Photonics 3: 2089–2095. Available: http://dx.doi.org/10.1021/acsphotonics.6b00457.
SponsorsWe acknowledge the financial support from King Abdulaziz City for Science and Technology (KACST), Grant No. KACST TIC R2-FP-008. This work is partially supported by King Abdullah University of Science and Technology (KAUST) baseline funding, BAS/1/1614-01-01.
PublisherAmerican Chemical Society (ACS)