Candela-class high-brightness InGaN/AlGaN double-heterostructure blue-light-emitting diodes

Nakamura, Shuji; Mukai, Takashi; Senoh, Masayuki

doi:10.1063/1.111832

Cited by 3,717 publications

(1,795 citation statements)

References 18 publications

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“…6,7) Few single-crystal GaN substrates have been fabricated until recently and, consequently, most GaN-based devices had been grown on heterogeneous substrates such as sapphire, SiC, or Si. [8][9][10][11][12] Additionally, the highpurity epitaxial layers of GaN that are needed for drift layers of vertical-type power devices are difficult to grow by conventional metal-organic chemical vapor deposition (MOCVD), because of the inevitable incorporation of carbon from metalorganic sources, 5,[13][14][15] despite the great success of MOCVD in the commercialization of optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

Fujikura

Konno

Yoshida

et al. 2017

Jpn. J. Appl. Phys.

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Thick (20–30 µm) layers of highly pure GaN with device-quality smooth as-grown surfaces were prepared on freestanding GaN substrates by using our advanced hydride-vapor-phase epitaxy (HVPE) system. Removal of quartz parts from the HVPE system markedly reduced concentrations of residual impurities to below the limits of detection by secondary-ion mass spectrometry. Appropriate gas-flow management in the HVPE system realized device-quality, smooth, as-grown surfaces with an excellent uniformity of thickness. The undoped GaN layer showed insulating properties. By Si doping, the electron concentration could be controlled over a wide range, down to 2 × 1014 cm−3, with a maximum mobility of 1150 cm2·V−1·s−1. The concentration of residual deep levels in lightly Si-doped layers was in the 1014 cm−3 range or less throughout the entire 2-in. wafer surface. These achievements clearly demonstrate the potential of HVPE as a tool for epitaxial growth of power-device structures.

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Section: Introductionmentioning

confidence: 99%

Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

Fujikura

Konno

Yoshida

et al. 2017

Jpn. J. Appl. Phys.

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“…(activation energy DE = 0.34 eV) has shown to be better than nitride compounds (DE & 0.25 eV) based on thermal quenching of emission intensity [175]. Apart from the temperature effect, the relative emission intensity of K 2 [175] or the formation of the MnO 2 phase [174]. These materials are very interesting phosphors.…”

Section: Red Phosphors-other Hostsmentioning

confidence: 99%

“…It is widely accepted that solid state lighting (SSL) will replace the old technologies that have been phased out (incandescent lamps) or are problematic from an environmental point of view (compact fluorescent lamps) [1]. The invention of bright-blue LEDs (light emitting diodes) by Nakamura and others in the mid-1990s [2,3] has led to the development of devices capable to produce white light in a reliable and efficient way, based on inorganic phosphors [4]. Presently, pcLED (phosphor converted light emitting diode) lamps are characterized by a number of important advantages compared to older generations of lamps, as they contain no highly toxic mercury [5], turn on instantly, are mechanically robust, have a longer life expectancy (up to 25,000-30,000 h) and especially have a higher energetic efficiency.…”

Section: Introductionmentioning

confidence: 99%

Inorganic Phosphor Materials for Lighting

2016

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This chapter addresses the development of inorganic phosphor materials capable of converting the near UV or blue radiation emitted by a light emitting diode to visible radiation that can be suitably combined to yield white light. These materials are at the core of the new generation of solid-state lighting devices that are emerging as a crucial clean and energy saving technology. The chapter introduces the problem of white light generation using inorganic phosphors and the structureproperty relationships in the broad class of phosphor materials, normally containing lanthanide or transition metal ions as dopants. Radiative and non-radiative relaxation mechanisms are briefly described. Phosphors emitting light of different colors (yellow, blue, green, and red) are described and reviewed, classifying them in different chemical families of the host (silicates, phosphates, aluminates, borates, and non-oxide hosts). This research field has grown rapidly and is still growing, but the discovery of new phosphor materials with optimized properties (in terms of emission efficiency, chemical and thermal stability, color, purity, and cost of fabrication) would still be of the utmost importance.

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“…As wide-band-gap semiconductors, they are used in a wide range of technological applications, in microwave communication, lasers, detectors, light emitting diodes, water/air purification in UV range, etc. [1,2]. After the synthesis of graphene [3], questions have been raised as to whether group IV elemental and group III-V compound semiconductors can form stable single-layer (SL) graphenelike structures, despite the fact that they do not have layered structures like graphite.…”

Section: Introductionmentioning

confidence: 99%

Single layers and multilayers of GaN and AlN in square-octagon structure: Stability, electronic properties, and functionalization

et al. 2017

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Further to planar single-layer hexagonal structures, GaN and AlN can also form free-standing, single-layer structures constructed from squares and octagons. We performed an extensive analysis of dynamical and thermal stability of these structures in terms of ab initio finite-temperature molecular dynamics and phonon calculations together with the analysis of Raman and infrared active modes. These single-layer square-octagon structures of GaN and AlN display directional mechanical properties and have wide, indirect fundamental band gaps, which are smaller than their hexagonal counterparts. These density functional theory band gaps, however, increase and become wider upon correction. Under uniaxial and biaxial tensile strain, the fundamental band gaps decrease and can be closed. The electronic and magnetic properties of these single-layer structures can be modified by adsorption of various adatoms, or by creating neutral cation-anion vacancies. The single-layer structures attain magnetic moment by selected adatoms and neutral vacancies. In particular, localized gap states are strongly dependent on the type of vacancy. The energetics, binding, and resulting electronic structure of bilayer, trilayer, and three-dimensional (3D) layered structures constructed by stacking the single layers are affected by vertical chemical bonds between adjacent layers. In addition to van der Waals interaction, these weak vertical bonds induce buckling in planar geometry and enhance their binding, leading to the formation of stable 3D layered structures. In this respect, these multilayers are intermediate between van der Waals solids and wurtzite crystals, offering a wide range of tunability.

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Candela-class high-brightness InGaN/AlGaN double-heterostructure blue-light-emitting diodes

Cited by 3,717 publications

References 18 publications

Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

Inorganic Phosphor Materials for Lighting

Single layers and multilayers of GaN and AlN in square-octagon structure: Stability, electronic properties, and functionalization

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