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Related papers: Excitons in InGaAs Quantum Dots without Electron W…

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Tuning GaAs-based quantum emitters to telecom wavelengths makes it possible to use the existing mature technology for applications in, e.g., long-haul ultra-secure communication in the fiber networks. A promising method re-developed…

We study theoretically the performance of electrically pumped self-organized quantum dots as a gain material in the mid-IR range at room temperature. We analyze an AlGaAs/InGaAs based structure composed of dots-in-a-well sandwiched between…

Materials Science · Physics 2014-10-27 Stephan Michael , Weng W. Chow , Hans Christian Schneider

Van der Waals heterostructures usually formed using atomic thin transition metal dichalcogenides (TMDCs) with a direct bandgap in the near-infrared to the visible range are promising candidates for low-dimensional optoelectronic…

Mesoscale and Nanoscale Physics · Physics 2018-09-21 Guanghui Cheng , Baikui Li , Chunyu Zhao , Xin Yan , Hong Wang , Kei May Lau , Jiannong Wang

Using atomistic pseudopotential and configuration-interaction many-body calculations, we predict a metal-nonmetal transition and an excitonic ground state in the InAs/InSb quantum dot (QD) system. For large dots, the conduction band minimum…

Materials Science · Physics 2009-11-10 Lixin He , Gabriel Bester , Alex Zunger

Semiconductor nano-crystals, known as quantum dots (QDs), have attracted significant attention for their unique fluorescence properties. Under continuous excitation, QDs emit photons with intricate intensity fluctuation: the intensity of…

Applied Physics · Physics 2025-04-28 Xin Yang , Hawi Nyiera , Yonglei Sun , Jing Zhao , Kun Chen

We present a controlled mechanical exfoliation technique for bulk 3D topological insulators that yields atomically clean ultrathin flakes, enabling quantum well states (QWS) of Dirac electrons to be clearly resolved. Achieving reliable…

Mesoscale and Nanoscale Physics · Physics 2025-11-26 Shreyashi Sinha , Shantanu Pathak , Saswata Bhattacharya , Sujit Manna

We present the direct heteroepitaxial growth of high-quality InGaAs quantum dots on silicon, enabling scalable, cost-effective quantum photonics devices compatible with CMOS technology. GaAs heterostructures are grown on silicon via a GaP…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 Imad Limame , Peter Ludewig , Ching-Wen Shih , Marcel Hohn , Chirag C. Palekar , Wolfgang Stolz , Stephan Reitzenstein

The rapidly developing quantum communication technology requires deterministic quantum emitters that can generate single photons and entangled photon pairs in the third telecom window, in order to be compatible with existing optical fiber…

We demonstrate a new quantum-confined semiconductor material based on GaSb quantum dots (QDs) embedded in single-crystalline AlGaSb matrix by filling droplet-etched nanoholes. The droplet-mediated growth mechanism allows formation of low QD…

Mesoscale and Nanoscale Physics · Physics 2021-05-18 Abhiroop Chellu , Joonas Hilska , Jussi-Pekka Penttinen , Teemu Hakkarainen

Excitons in semiconductors may form correlated phases at low temperatures. We report the observation of an exciton liquid in GaAs/AlGaAs coupled quantum wells. Above a critical density and below a critical temperature the photogenerated…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Michael Stern , Vladimir Umansky , Israel Bar-Joseph

In contrast to interband excitons in undoped quantum wells, doped quantum wells do not display sharp resonances due to excitonic bound states. In these systems the effective Coulomb interaction between electrons and holes typically only…

In this cross-sectional scanning tunneling microscopy study we investigated various techniques to control the shape of self-assembled quantum dots (QDs) and wetting layers (WLs). The result shows that application of an indium flush during…

Mesoscale and Nanoscale Physics · Physics 2018-02-14 J. G. Keizer , M. Bozkurt , J. Bocquel , P. M. Koenraad , T. Mano , T. Noda , K. Sakoda , E. C. Clark , M. Bichler , G. Abstreiter , J. J. Finley , W. Lu , T. Rohel , H. Folliot , N. Bertru

We present results of correlated pseudopotential calculations of an exciton in a pair of vertically stacked InGaAs/GaAs dots. Competing effects of strain, geometry, and band mixing lead to many unexpected features missing in contemporary…

Materials Science · Physics 2012-03-08 Gabriel Bester , J. Shumway , Alex Zunger

We demonstrate that the exciton and biexciton emission energies as well as exciton fine structure splitting (FSS) in single (In,Ga)As/GaAs quantum dots (QDs) can be efficiently tuned using hydrostatic pressure in situ in an optical cryostat…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Xuefei Wu , Hai Wei , Xiuming Dou , Kun Ding , Ying Yu , Haiqiao Ni , Zhichuan Niu , Yang Ji , Shushen Li , Desheng Jiang , Guangcan Guo , Lixin He , Baoquan Sun

Tailoring electronic and optical properties of self-assembled InAs quantum dots (QDs) is a critical limit for the design of several QD-based optoelectronic devices operating in the telecom frequency range. We describe how a fine control of…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 Vittorianna Tasco , Muhammad Usman , Milena De Giorgi , Adriana Passaseo

We present atomistic computations within an empirical pseudopotential framework for the electron $s$-shell ground state $g$ tensor of InGaAs quantum dots (QDs) embedded to host matrices that grant electronic confinement. A large structural…

Mesoscale and Nanoscale Physics · Physics 2021-04-13 Mustafa Kahraman , Ceyhun Bulutay

The investigation of small size embedded nanostructures, by a combination of complementary anomalous diffraction techniques, is reported. GaN Quantum Dots (QDs), grown by molecular beam epitaxy in a modified Stranski-Krastanow mode, are…

Materials Science · Physics 2009-11-11 J. Coraux , V. Favre-Nicolin , H. Renevier , M. G. Proietti , B. Daudin

Materials with optical gain in the infrared are of paramount importance for optical communications, medical diagnostics1 and silicon photonics2,3 . The current technology is based either on costly III-V semiconductors that are not…

We explore the Bi-surfactant-directed self-assembly and structure of InAs quantum dots grown on GaAs(110) by molecular beam epitaxy. The addition of a Bi flux during InAs deposition changes the InAs growth mode from two-dimensional (2D)…

Materials Science · Physics 2020-01-08 Ryan B. Lewis , Achim Trampert , Esperanza Luna , Jesús Herranz , Carsten Pfüller , Lutz Geelhaar

We report on a temporal evolution of photoluminescence (PL) spectroscopy of CuInS$_{2}$/ZnS colloidal quantum dots (QDs) by drop-casting on SiO$_{2}$/Si substrates and high quality factor microdisks (MDs) under different atmospheric…

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