Journal ArticleDOI
Origin of defect-insensitive emission probability in In-containing (Al,In,Ga)N alloy semiconductors.
Shigefusa F. Chichibu,Akira Uedono,Akira Uedono,Takeyoshi Onuma,Benjamin A. Haskell,Arpan Chakraborty,T. Koyama,Paul T. Fini,Stacia Keller,Steven P. DenBaars,James S. Speck,Umesh K. Mishra,Shuji Nakamura,Shigeo Yamaguchi,Shigeo Yamaguchi,Satoshi Kamiyama,Hiroshi Amano,Isamu Akasaki,Jung Han,Takayuki Sota +19 more
TLDR
Here it is explained why In-containing (Al,In,Ga)N bulk films exhibit a defect-insensitive emission probability, and it is concluded that localizing valence states associated with atomic condensates of In–N preferentially capture holes, which have a positive charge similar to positrons.Abstract:
Group-III-nitride semiconductors have shown enormous potential as light sources for full-colour displays, optical storage and solid-state lighting. Remarkably, InGaN blue- and green-light-emitting diodes (LEDs) emit brilliant light although the threading dislocation density generated due to lattice mismatch is six orders of magnitude higher than that in conventional LEDs. Here we explain why In-containing (Al,In,Ga)N bulk films exhibit a defect-insensitive emission probability. From the extremely short positron diffusion lengths (<4 nm) and short radiative lifetimes of excitonic emissions, we conclude that localizing valence states associated with atomic condensates of In-N preferentially capture holes, which have a positive charge similar to positrons. The holes form localized excitons to emit the light, although some of the excitons recombine at non-radiative centres. The enterprising use of atomically inhomogeneous crystals is proposed for future innovation in light emitters even when using defective crystals.read more
Citations
More filters
Journal ArticleDOI
Phosphors in phosphor-converted white light-emitting diodes: Recent advances in materials, techniques and properties
TL;DR: In this article, the most recent advances in the synthesis and application of phosphors for white light-emitting diodes (pc-WLEDs) with emphasis specifically on: (a) principles to tune the excitation and emission spectra of the phosphors: prediction according to crystal field theory, and structural chemistry characteristics (e.g. covalence of chemical bonds, electronegativity, and polarization effects of element); (b) pc-W LEDs with phosphors excited by blue-LED chips: phosphor characteristics, structure, and activated ions
Journal ArticleDOI
Auger recombination in InGaN measured by photoluminescence
TL;DR: In this paper, the Auger recombination coefficient in quasi-bulk InxGa1−xN (x∼9%−15%) layers grown on GaN (0001) is measured by a photoluminescence technique.
Journal ArticleDOI
Efficiency droop in nitride-based light-emitting diodes
TL;DR: In this paper, the authors provide a snapshot of the current state of droop research, reviews currently discussed droop mechanisms, contextualizes them, and proposes a simple yet unified model for the LED efficiency droop.
Journal ArticleDOI
LEDs for Solid-State Lighting: Performance Challenges and Recent Advances
TL;DR: In this paper, the authors review LED performance targets that are needed to achieve these benefits and highlight some of the remaining technical challenges, and describe recent advances in LED materials and novel device concepts that show promise for realizing the full potential of LED-based white lighting.
Journal ArticleDOI
Electrically pumped continuous-wave III–V quantum dot lasers on silicon
Siming Chen,Wei Li,Jiang Wu,Qi Jiang,Mingchu Tang,Samuel Shutts,Stella N. Elliott,Angela Sobiesierski,Alwyn J. Seeds,Ian M. Ross,Peter Michael Smowton,Huiyun Liu +11 more
TL;DR: In this paper, the authors demonstrate continuous-wave InAs/GaAs quantum dot lasers directly grown on silicon substrates with a low threshold current density of 62.5 cm−2, a room-temperature output power exceeding 105mW and operation up to 120°C.
References
More filters
Book
The Blue Laser Diode: GaN based Light Emitters and Lasers
Shuji Nakamura,Gerhard Fasol +1 more
TL;DR: The physics of gallium nitrides and related compounds GaN growth p-Type GaN obtained by electron beam irradiation n-Type GAN p-type GaN InGaN Zn and Si co-doped GaN double-heterostructure blue and blue green LEDs inGaN single-quantum-well structure LEDs room-temperature pulsed operation of laser diodes emission mechanisms of LEDs and LDs room temperature CW operation of InGAN MQW LDs latest results as discussed by the authors.
Journal ArticleDOI
First-principles calculations for defects and impurities: Applications to III-nitrides
TL;DR: In this paper, the authors describe the state-of-the-art computational methodology for calculating the structure and energetics of point defects and impurities in semiconductors and pay particular attention to computational aspects which are unique to defects or impurities, such as how to deal with charge states and how to describe and interpret transition levels.
Journal ArticleDOI
Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes
Patrick Waltereit,Oliver Brandt,Achim Trampert,Holger T. Grahn,J. Menniger,Manfred Ramsteiner,M. Reiche,Klaus H. Ploog +7 more
TL;DR: It is demonstrated that the epitaxial growth of GaN/(Al,Ga)N on tetragonal LiAlO2 in a non-polar direction allows the fabrication of structures free of electrostatic fields, resulting in an improved quantum efficiency, which is expected to pave the way towards highly efficient white LEDs.
Journal ArticleDOI
Band-Edge Electroabsorption in Quantum Well Structures: The Quantum-Confined Stark Effect
David A. B. Miller,Daniel S. Chemla,T. C. Damen,Arthur C. Gossard,W. Wiegmann,Thomas H. Wood,Charles A. Burrus +6 more
TL;DR: In this article, the authors present theory and extended experimental results for the large shift in optical absorption in GaAs-AlGaAs quantum well structures with electric field perpendicular to the layers.
Journal ArticleDOI
Nitride-based semiconductors for blue and green light-emitting devices
Fernando Ponce,David P. Bour +1 more
TL;DR: In this article, the group III elements of the semiconducting nitrides have been used for the fabrication of high-efficiency solid-state devices that emit green and blue light.