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We study the exciton dynamics in an optically excited nanocrystal quantum dot. Multiple exciton formation is more efficient in nanocrystal quantum dots compared to bulk semiconductors due to enhanced Coulomb interactions and the absence of…

Mesoscale and Nanoscale Physics · Physics 2016-05-02 Fikeraddis A. Damtie , Andreas Wacker

Carrier multiplication (CM), a photo-physical process to generate multiple electron-hole pairs by exploiting excess energy of free carriers, is explored for efficient photovoltaic conversion of photons from the blue solar band,…

The spectroscopic properties of a spin polarized two-dimensional hole gas are studied in modulation doped (Cd,Mn)Te quantum wells. The giant Zeeman effect induces a significant spin splitting even at very small values of the applied field.…

Materials Science · Physics 2014-01-29 P. Kossacki , H. Boukari , M. Bertolini , D. Ferrand , J. Cibert , S. Tatarenko , J. A. Gaj , B. Deveaud , V. Ciulin , M. Potemski

Mechanisms of nonradiative recombination of electron-hole complexes in Cd(Mn)Se/Zn(Mn)Se quantum dots accompanied by interconfigurational excitations of Mn$^{2+}$ ions are analyzed within the framework of single electron model of deep {\it…

Mesoscale and Nanoscale Physics · Physics 2010-08-25 A. V. Chernenko , A. S. Brichkin , N. A. Sobolev , M. C. Carmo

The superfluid phase and Coulomb drag effect caused by the pairing in the system of spatially separated electrons and holes in two coaxial cylindrical nanotubes are predicted. It is found that the drag resistance as a function of…

Superconductivity · Physics 2013-12-31 Oleg L. Berman , Ilya Grigorenko , Roman Ya. Kezerashvili

We study the emission of individual quantum dots in CdTe/ZnTe samples doped with a low concentration of Cr. In addition to dots with a photoluminescence (PL) split by the exchange interaction with a magnetic Cr atom, we observe another type…

Mesoscale and Nanoscale Physics · Physics 2019-11-27 L. Besombes , H. Boukari , V. Tiwari , A. Lafuente-Sampietro , M. Sunaga , K. Makita , S. Kuroda

Employing the interband exciton scattering model, we have performed a numerical study of the direct photogeneration and population relaxation processes contributing to carrier multiplication (CM) in nanocrystalline and bulk PbSe. We argue…

Mesoscale and Nanoscale Physics · Physics 2016-11-25 Kirill A. Velizhanin , Andrei Piryatinski

Understanding the carrier excitation and transport processes at the single-charge level plays a key role in quantum-dot-based solar cells and photodetectors. Here, we report on Coulomb-induced giant photocurrent enhancement of positive…

Mesoscale and Nanoscale Physics · Physics 2019-02-13 Kai Peng , Shiyao Wu , Xin Xie , Jingnan Yang , Chenjiang Qian , Feilong Song , Sibai Sun , Jianchen Dang , Yang Yu , Shushu Shi , Jiongji He , Xiulai Xu

We report semi-empirical pseudopotential calculations of emission spectra of charged excitons and biexcitons in CdSe nanocrystals. We find that the main emission peak of charged multiexcitons - originating from the recombination of an…

Materials Science · Physics 2009-11-11 M. C. Troparevsky , A. Franceschetti

In organic photovoltaics, the mechanism by which free electrons and holes are generated overcoming the Coulomb attraction is a currently much debated topic. To elucidate this mechanism at a molecular level, we carried out a combined…

Chemical Physics · Physics 2013-09-12 Hiroyuki Tamura , Irene Burghardt

We propose a novel mechanism for photogeneration of multiexcitons by single photons (carrier multiplication) in semiconductor nanocrystals. In this mechanism, the Coulomb interaction between two valence-band electrons involving their…

Mesoscale and Nanoscale Physics · Physics 2007-07-17 Valery I. Rupasov , Victor I. Klimov

The charging energy of a quantum dot is measured through the effect of its potential on the conductance of a second dot. This technique allows a measurement of the scaling of the dot's charging energy with the conductance of the tunnel…

Condensed Matter · Physics 2009-10-28 L. W. Molenkamp , K. Flensberg , M. Kemerink

Using atomistic pseudopotential wave functions we calculate the electron and hole charging energies of InAs quantum dots. We find that the charging energies depend strongly on the dielectric constant epsilon_out of the surrounding material,…

Materials Science · Physics 2007-05-23 Alberto Franceschetti , Andrew Williamson , Alex Zunger

In a quantum dot with dozens of electrons, an approximation beyond Tamm-Dankoff is used to construct the quantum states with an additional electron-hole pair, i.e. the "excitonic" states. The lowest states mimic the non-interacting…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Alexander Odriazola , Alain Delgado , Augusto Gonzalez

Electron-hole correlation in quantum-dot quantum wells (QDQW's) is investigated by incorporating Coulomb and exchange interactions into an empirical tight-binding model. Sufficient electron and hole single-particle states close to the band…

Materials Science · Physics 2009-11-10 Rui-Hua Xie , Garnett W. Bryant , Seungwon Lee , W. Jaskolski

Energy-time entangled photons provide new opportunities for controlling multiphoton absorption beyond classical limits. Here, we investigate biexciton generation in nanocrystal quantum dots driven by energy-time-entangled quantum light…

Chemical Physics · Physics 2026-05-27 Kaiyue Peng , Chieh Tsao , Hendrik Utzat , Eran Rabani

Identifying the behavior of photoexcited carriers is one method for empirically boosting their transfer efficiencies in doped double quantum dots (DQDs) photocells. The photoexcited carriers transfer qualities were assessed in this study by…

Mesoscale and Nanoscale Physics · Physics 2024-03-12 Sheng-Nan Zhu , Shun-Cai Zhao , Lin-Jie Chen , Qing Fang

We measure the electron escape-rate from surface-acoustic-wave dynamic quantum dots (QDs) through a tunnel barrier. Rate-equations are used to extract the tunnelling rates, which change by an order of magnitude with tunnel-barrier gate…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. R. Astley , M. Kataoka , C. J. B. Ford , C. H. W. Barnes , D. Anderson , G. A. C. Jones , I. Farrer , D. A. Ritchie , M. Pepper

We present an approach for the highly sensitive photon detection based on the quantum dots (QDs) operating at temperature of 77K. The detection structure is based on an AlAs/GaAs/AlAs double barrier resonant tunneling diode combined with a…

Quantum Physics · Physics 2009-11-13 Wangping Wang , Ying Hou , Dayuan Xiong , Ning Li , Wei Lu

We study the effect of Coulomb correlation on the emission properties of the ground state exciton in zincblende CdSe/ZnS core-shell and in wurtzite ZnO quantum dots. We validate our theory model by comparing results of computed exciton…

Mesoscale and Nanoscale Physics · Physics 2021-12-13 Petr Klenovský , Jakub Valdhans , Lucie Krejčí , Miroslav Valtr , Petr Klapetek , Olga Fedotova