English
Related papers

Related papers: Defect recombination induced by density-activated …

200 papers

III-V nitride semiconductors, represented by GaN, have attracted significant research attention. Driven by the growing interest in smart micro-displays, there is a strong desire to achieve enhanced light output from even smaller…

Crystallographic point defects (PDs) can dramatically decrease the efficiency of optoelectronic semiconductor devices, many of which are based on quantum well (QW) heterostructures. However, spatially resolving individual non-radiative PDs…

About a year ago, two independent experiments [1,2], imaging indirect exciton luminescence from doped double quantum wells under applied bias and optical excitation, reported a very intriguing observation: under certain experimental…

Condensed Matter · Physics 2013-05-29 R. Rapaport , Gang Chen , D. Snoke , Steve H. Simon , Loren Pfeiffer , Ken West , Y. Liu , S. Denev , .

We investigate the modification of the spontaneous emission dynamics and external quantum efficiency for self-assembled InGaAs quantum dots coupled to extended and localised photonic states in GaAs 2D-photonic crystals. The 2D-photonic…

Materials Science · Physics 2009-11-13 M. Kaniber , A. Kress , M. Bichler , R. Meyer , M. -C. Amann , J. J. Finley

The multiplication rates of hot carriers in CdSe quantum dots are quantified using an atomistic pseudopotential approach and first order perturbation theory. Both excited holes and electrons are considered, and electron-hole Coulomb…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Zhibin Lin , Alberto Franceschetti , Mark T. Lusk

A 3D analysis of the spontaneous decay of a single dipole embedded in a planar multilayer structure is given, with special emphasis on Kerr-tunable photonic band-gap materials for single-photon emission on demand. It is shown that the…

Quantum Physics · Physics 2016-08-16 Ho Trung Dung , Ludwig Knöll , Dirk-Gunnar Welsch

Solid-state ionic conduction is a key enabler of electrochemical energy storage and conversion. The mechanistic connections between material processing, defect chemistry, transport dynamics, and practical performance are of considerable…

Materials Science · Physics 2022-08-04 Andrey D. Poletayev , James A. Dawson , M. Saiful Islam , Aaron M. Lindenberg

There is a lack of highly efficient light emitting devices (LEDs) operating in the green spectral regime. The devices based on (In,Al)GaN show extremely high efficiencies in violet and blue colors but fall short for longer emission…

The kinetics of the charge carrier recombination in dye molecule-doped multilayer organic light-emitting diodes (OLEDs) was quantified by transient electroluminescence (EL). Three sets of dye molecules, such as derivatives of naphthalimide…

Materials Science · Physics 2014-11-13 Shengwei Shi , Feng Gao , Zhengyi Sun , Yiqiang Zhan , Mats Fahlman , Dongge Ma

We introduce a multiple-carrier-lifetime model (MCLM) for light-emitting diodes (LEDs) with non-uniform carrier distribution, such as in multiple-quantum-well (MQW) structures. By employing the MCLM, we successfully explain the modulation…

Applied Physics · Physics 2023-10-27 Xuefeng Li , Elizabeth DeJong , Rob Armitage , Daniel Feezell

Self-doping can not only suppress the photogenerated charge recombination of semiconducting quantum dots by self-introducing trapping states within the bandgap, but also provide high-density catalytic active sites as the consequence of…

We have carried out ab initio electronic structure calculations on graphane (hydrogenated graphene) with single and double vacancy defects. Our analysis of the density of states reveal that such vacancies induce the mid gap states and…

Materials Science · Physics 2010-02-11 Bhalchandra S. Pujari , D. G. Kanhere

Incorporation of manganese impurities into II-VI semiconductors results in a dramatic change in their properties due to strong exchange interactions between the Mn ion and the semiconductor host. In colloidal quantum dots (QDs), these…

Materials Science · Physics 2024-12-24 Jungchul Noh , Clément Livache , Donghyo Hahm , Valerio Pinchetti , Ho Jin , Changjo Kim , Victor I. Klimov

We report the direct observation of coupling between a single self-assembled InAs quantum dot and a wetting layer, based on strong diamagnetic shifts of many-body exciton states using magneto-photoluminescence spectroscopy. An extremely…

Silver nanoparticles dispersed on the surface of an inverted GaN LED were found to plasmonically enhance the near-bandedge emission. The resonant surface plasmon coupling led to a significant enhancement in the exciton decay rate and the…

Electron-hole generation and recombination rates for plasmon emission and absorption in Graphene are presented. The recombination times of carriers due to plasmon emission have been found to be in the tens of femtoseconds to hundreds of…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Farhan Rana , Jared H. Strait , Haining Wang , Christina Manolatou

Understanding the origin of hot carrier relaxation in nanowires (NWs) with one-dimensional (1D) geometry is significant for designing efficient hot carrier solar cells with such nanostructures. Here, we study the influence of Auger heating…

Mesoscale and Nanoscale Physics · Physics 2024-04-16 Hamidreza Esmaielpour , Nabi Isaev , Jonathan J. Finley , Gregor Koblmüller

We study the evolution of the absorption spectrum of a modulation doped GaAs/AlGaAs semiconductor quantum well with decreasing the carrier density. We find that there is a critical density which marks the transition from a Fermi edge…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 G. Yusa , H. Shtrikman , I. Bar-Joseph

Impurity-bound excitons in II-VI direct-bandgap semiconductors are promising optically active solid-state spin qubits that combine exceptional optical quantum efficiency with an ultra-low spin noise environment. Previous studies on single…

We report strong light emission from a room-temperature n-type unipolar-doped In0.53Ga0.47As/AlAs double-barrier resonant-tunneling diode (DBRTD) precisely at the In0.53Ga0.47As band-edge near 1650 nm. The emission characteristics are very…

Mesoscale and Nanoscale Physics · Physics 2018-04-23 E. R. Brown , W-D. Zhang , T. A. Growden , P. R. Berger , R. Droopad