Physics of Efficiency Droop in GaN:Eu Light-Emitting Diodes

Fragkos, Ioannis E.; Dierolf, Volkmar; Fujiwara, Yoshihiro; Tansu, Nelson

doi:10.1038/s41598-017-17033-6

Cited by 7 publications

(3 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The internal quantum efficiency of a GaN/GaN:Eu/GaN device was calculated in a similar approach to ref. 46 . The introduction of surface plasmon coupled active region in GaN:Eu results in an order of magnitude increase in the internal quantum efficiency of the electrically-driven devices, and provides a reduction of efficiency-droop up to relatively high current density ( J ).…”

Section: Impact Of Purcell Factor On Internal Quantum Efficiencymentioning

confidence: 99%

Surface Plasmon Coupling in GaN:Eu Light Emitters with Metal-Nitrides

Fragkos

Tansu

2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

Metal-nitrides of hafnium nitride (HfN), zirconium nitride (ZrN) and titanium nitride (TiN) are investigated as plasmonic materials to enhance the internal quantum efficiency of a GaN:Eu red light emitter. Theoretical calculations are performed to evaluate the surface plasmon polariton dispersion relation and Purcell enhancement factor for a single metal-nitride layer on top of the GaN:Eu emitter. Our findings suggest that among the metal-nitrides investigated in this study, TiN is the most promising candidate for use as plasmonic material to increase the internal quantum efficiency in GaN:Eu red light emitters.

show abstract

Section: Impact Of Purcell Factor On Internal Quantum Efficiencymentioning

confidence: 99%

Surface Plasmon Coupling in GaN:Eu Light Emitters with Metal-Nitrides

Fragkos

Tansu

2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…With the advantages over other conventional light sources such as incandescent bulbs, halogen lamps, xenon HID lamps, LED has progressed rapidly to be applied in general lighting [2] and many special fields such as plant lighting [3], automotive lighting [4], healthcare lighting [5] and visible light communication (VLC) [6]. However, the luminous intensity of a single LED package can't satisfy the high power and high illumination application because of the power limit of an individual LED package and its efficiency droop effect [7][8][9]. So, the LED array prepared by several arranged LED individuals [10][11][12] is emerged in high power applications, such as street lighting, automotive lighting, detector lighting, etc.…”

Section: Introductionmentioning

confidence: 99%

Dynamic prediction of optical and chromatic performances for a light-emitting diode array based on a thermal-electrical-spectral model

Fan¹,

Chen²,

Yuan³

et al. 2020

Opt. Express

View full text Add to dashboard Cite

Light-emitting diode (LED) arrays have attracted increased attention in the area of high power intelligent automotive headlamps because of their superiority in disposing of the power limit of an individual LED package and controllably luminous intensity and illumination pattern. The optical and chromatic performances of an LED array do not equal to the sum of individual LED packages' performances, as the thermal interactions between individual LED packages can't be ignored in the actual application. This paper presents a thermal-electrical-spectral (TES) model to dynamically predict the optical and chromatic performances of the LED array. The thermal-electrical (TE) model considering the thermal coupling effect in the LED array is firstly proposed to predict the case temperature of each individual LED package, and the Spectral power distributions (SPDs) of individual LED package is then decomposed by the extended Asym2sig model to extract the spectral characteristic parameters. Finally, the experimental measurements of the designed LED arrays operated under usage conditions are used to verify the TES model. Some validation case studies show that the prediction accuracy of the proposed TES model, which is expressed as a quadratic polynomial function of current and case temperature, can be achieved higher than 95%. Therefore, it can be concluded that this TES model offers a convenient method with high accuracy to dynamically predict the optical and chromatic performances of LED arrays at real usages.

show abstract

“…The incorporation of rare earth elements, such as Er or Eu, into semiconductor hosts gives rise to sharp, atomiclike and temperature independent emission lines under either optical or electrical excitation [1,2,[9][10][11]. Er ions with intra-4f shell transitions from its first excited state ( 4 I 13/2 ) to the ground state ( 4 I 15/2 ) produce 1.5 µm emission, which falls within the minimum loss window of optical fibers for optical communications.…”

Section: Introductionmentioning

confidence: 99%