Enhanced carrier confinement in AlInGaN-InGaN quantum wells in near ultraviolet light-emitting diodes

Baek, Seong‐Ho; Kim, Jeom-Oh; Kwon, Min‐Ki; Park, Il‐Kyu; Na, Seok‐In; Kim, Ja‐Yeon; Kim, Bongjin; Park, Seong-Ju

doi:10.1109/lpt.2006.875322

Cited by 29 publications

(5 citation statements)

References 12 publications

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“…Another challenge in exploring phosphors for pc-WLEDs is to reduce the energy gap between the 4f level and the lowest 5d level to below 3.1 eV (400 nm) to match the emission of InGaN LED chips . This energy gap requirement demands for scientists to explore new oxide host crystals with shorter activator–anion bond lengths and high polyhedral distortion .…”

Section: Introductionmentioning

confidence: 99%

Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy

et al. 2019

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The luminescence of rare earth ions (Eu 2+ , Ce 3+ , and Eu 3+ )-doped inorganic solids is attractive for the screening of phosphors applied in solid-state lighting and displays and significant to probe the occupied crystallographic sites in the lattice also offering new routes to photoluminescence tuning. Here, we report on the discovery of the Eu-and Ce-activated K 3 YSi 2 O 7 phosphors. K 3 YSi 2 O 7 :Eu is effectively excited by 450 nm InGaN blue light-emitting diodes (LEDs) and displays an orange-red emission originated from characteristic transitions of both Eu 2+ and Eu 3+ , while K 3 YSi 2 O 7 :Ce 3+ shows green emission upon 394 nm nearultraviolet (NUV) light excitation. Rietveld refinement verifies the successful doping of the activators, and density functional theory (DFT) calculations further support that Eu 2+ occupies both K1 and Y2 crystallographic sites, while Ce 3+ and Eu 3+ only occupy the Y2 site; hence, the broad-band red emission of Eu 2+ are attributed to a small DFT band gap (3.69 eV) of K 3 YSi 2 O 7 host and a selective occupancy of Eu 2+ in a highly distorted K1 site and a high crystal field splitting around Y2 sites. The white LEDs device utilizing orange-red-emitting K 3 YSi 2 O 7 :Eu and green-emitting K 3 YSi 2 O 7 :Ce 3+ exhibits an excellent CRI of 90.1 at a correlated color temperature of 4523 K. Our work aims at bridging multivalent Eu 2+ /Eu 3+ and Ce 3+ site occupancy in the same host to realize photoluminescence tuning and especially exposes new ways to explore new phosphors with multicolor emission pumped by blue and NUV light for white LEDs.

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Section: Introductionmentioning

confidence: 99%

Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy

et al. 2019

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“…[6][7][8] The various modification meth-ods on quantum well structures, such as the polarizationmatched AlGaInN or InGaN barriers, have demonstrated that polarization effects can be effectively eliminated and the radiative recombination rate is improved. [9][10][11][12] However, it is difficult to grow AlInGaN layers with high crystalline quality due to the differences between optimal incorporation conditions for growth of AlN and InN. Also, the crystalline quality of active layers could be worse as more InGaN barriers and wells are deposited repeatedly due to the accumulation of large compressive strain.…”

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confidence: 99%

Enhanced internal quantum efficiency in graphene/InGaN multiple-quantum-well hybrid structures

et al. 2012

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“…8b. Earlier works 58,59 have reported that thinner channel layer tends to have narrower potential well and lowering the thickness causes the energy levels in the quantum states to be filled up completely. Therefore, electrons will be forced out in to the buffer regardless of back barrier effect.…”

Section: Optimization and Scaling Of Channel Layer Thicknessmentioning

confidence: 99%

Optimization of Graded AlInN/AlN/GaN HEMT Device Performance Based on Quaternary Back Barrier for High Power Application

Rahman

Othman

Hatta

et al. 2017

ECS J. Solid State Sci. Technol.

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Conventional HEMT devices perform poorly especially in the Ka band due to buffer electron spillage and poor confinement. Microwave and defense industries are key consumers of electronics and require transistors to be free from adverse effects namely current collapse in the drain for elevated power application. This work investigates the effects of graded AlInN barrier together with emerging quaternary material on device output in providing an alternate solution to industrial needs. The Aluminum mole fraction had been linearly increased along the graded section, with the addition of the AlInGaN back barrier. Improved current density and electric field demonstrate potential for high linearity application. The back barrier improves electron confinement in the channel while the effect of graded barrier was found to enhance output and transfer characteristics where the former incremented by almost 60% and the latter by around 1.9 A/mm, compared to conventional devices. Concentration of 2-dimensional electron gas (2DEG) had elevated by four times in the channel region with speed of electrons at 17.8 × 106 cms−1 in the back barrier. Overall, it has been demonstrated that the optimized AlInN/GaN-based HEMT shows excellent electrical characteristics and is a promising alternative to AlGaN/GaN HEMT for high frequency and high power application.

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Enhanced carrier confinement in AlInGaN-InGaN quantum wells in near ultraviolet light-emitting diodes

Cited by 29 publications

References 12 publications

Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy

Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy

Enhanced internal quantum efficiency in graphene/InGaN multiple-quantum-well hybrid structures

Optimization of Graded AlInN/AlN/GaN HEMT Device Performance Based on Quaternary Back Barrier for High Power Application

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Enhanced carrier confinement in AlInGaN-InGaN quantum wells in near ultraviolet light-emitting diodes

Cited by 29 publications

References 12 publications

Engineering of K3YSi2O7To Tune Photoluminescence with Selected Activators and Site Occupancy

Engineering of K3YSi2O7To Tune Photoluminescence with Selected Activators and Site Occupancy

Enhanced internal quantum efficiency in graphene/InGaN multiple-quantum-well hybrid structures

Optimization of Graded AlInN/AlN/GaN HEMT Device Performance Based on Quaternary Back Barrier for High Power Application

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Product

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Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy

Engineering of K₃YSi₂O₇To Tune Photoluminescence with Selected Activators and Site Occupancy