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Related papers: Bound exciton and free exciton states in GaSe thin…

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Single air-suspended carbon nanotubes (length 2 - 5 microns) exhibit high optical quantum efficiency (7 - 20%) for resonant pumping at low intensities. Under ultrafast excitation, the photoluminescence dramatically saturates for very low…

Materials Science · Physics 2010-01-14 Y. -F. Xiao , T. Q. Nhan , M. W. B. Wilson , J. M. Fraser

We report nearly complete preservation of "spin memory" between optical absorption and photoluminescence (PL) in nanometer slabs of GaSe pumped with up to 0.2 eV excess energy. At cryogenic temperatures, the initial degree of circular…

Mesoscale and Nanoscale Physics · Physics 2015-05-22 Yanhao Tang , Wei Xie , Krishna C. Mandal , John A. McGuire , Chih-Wei Lai

Theoretical and numerical calculations of the optical absorption spectra of excitons interacting with longitudinal-optical phonons in quasi-2D polar semiconductors are presented. In II-VI semiconductor quantum wells, exciton binding energy…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 F. J. Rodriguez

The results of investigation of bulk GaAs photoluminescence are presented taken from near-surface layers of different thicknesses using for excitation the light with the wavelengths which are close but some greater than the excitonic…

Materials Science · Physics 2022-07-08 V. A. Yuryev , V. P. Kalinushkin , A. V. Zayats , Yu. A. Repeyev , V. G. Fedoseyev

We report nearly complete preservation of "spin memory" between optical absorption and photoluminescence (PL) in nanometer slabs of GaSe pumped with 0.2 eV excess energy. At cryogenic temperatures, the initial degree of circular…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Yanhao Tang , Wei Xie , Krishna C. Mandal , John A. McGuire , C. W. Lai

Cross-polarized absorption peaks of isolated single-walled carbon nanotubes were observed by a polarized photoluminescence excitation (PLE) spectroscopy. Using a simple theory for PL anisotropy, the observed PLE spectra are decomposed into…

Materials Science · Physics 2009-11-11 Yuhei Miyauchi , Mototeru Oba , Shigeo Maruyama

We present the micro-photoluminescence ($\mu$PL) and micro-reflectance contrast spectroscopy studies on thin films of MoSe2 with layer thicknesses ranging from a monolayer (1L) up to 5L. The thickness dependent evolution of the ground and…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Ashish Arora , Karol Nogajewski , Maciej R. Molas , Maciej Koperski , Marek Potemski

In an effort to elucidate the spin (rather than charge) degrees of freedom in colloidal semiconductor nanocrystal quantum dots, we report on a series of static and time-resolved photoluminescence measurements of colloidal CdSe quantum dots…

Materials Science · Physics 2007-05-23 Madalina Furis , Jennifer Hollingsworth , Victor I. Klimov , Scott A. Crooker

The coupling with the lattice vibrations is shown to drastically modify the state--of--the--art picture of the excitonic states based on a frozen atom approximation. The zero--point vibrations renormalize the bare energies and optical…

Materials Science · Physics 2009-11-13 Andrea Marini

Observations of polariton condensation in semiconductor microcavities suggest that polaritons can be exploited as a novel type of laser with low input-power requirements. The low-excitation regime is approximately equivalent to thermal…

Mesoscale and Nanoscale Physics · Physics 2013-07-16 Tomoyuki Horikiri , Yasuhiro Matsuo , Yutaka Shikano , Andreas Loeffler , Sven Hoefling , Alfred Forchel , Yoshihisa Yamamoto

Screening due to surrounding dielectric medium reshapes the electron-hole interaction potential and plays a pivotal role in deciding the binding energies of strongly bound exciton complexes in quantum confined monolayers of transition metal…

Mesoscale and Nanoscale Physics · Physics 2017-08-16 Garima Gupta , Sangeeth Kallatt , Kausik Majumdar

The photoluminescence (PL) and PL excitation (PLE) spectra of CdTe/ZnTe asymmetric double quantum well (QW) structures are studied on a series of samples containing two CdTe layers with nominal thicknesses of 2 and 4 monolayers (ML) in the…

Mesoscale and Nanoscale Physics · Physics 2020-12-30 V. Agekyan , G. Budkin , M. Chukeev , N. Filosofov , G. Karczewski , A. Serov , A. Reznitsky

Exciton binding energy and excited states in monolayers of tungsten diselenide (WSe2) are investigated using the combined linear absorption and two-photon photoluminescence excitation spectroscopy. The exciton binding energy is determined…

Materials Science · Physics 2015-06-19 Keliang He , Nardeep Kumar , Liang Zhao , Zefang Wang , Kin Fai Mak , Hui Zhao , Jie Shan

We present a detailed investigation of the exciton and trion dynamics in naturally doped MoSe2 and WSe2 single atomic layers as a function of temperature in the range 10-300K under above band-gap laser excitation. By combining…

A recent single quantum wire is of sufficient quality to reveal new details of the photoluminescence (PL) evolution with increasing electron--hole (e--h) pair density. At a pair density of 3.6 $\times$ 10$^{3}$ cm$^{-1}$, the PL is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Masahiro Yoshita , Yuhei Hayamizu , Hidefumi Akiyama , Loren N. Pfeiffer , Ken W. West , Kenichi Asano , Tetsuo Ogawa

The photoluminescence dynamics of a microscopic gas of indirect excitons trapped in coupled quantum wells is probed at very low bath temperature (approximately 350 mK). Our experiments reveal the non linear energy relaxation characteristics…

Strongly Correlated Electrons · Physics 2015-05-20 Mathieu Alloing , Aristide Lemaitre , Francois Dubin

In a standard semiconductor laser, electrons and holes recombine via stimulated emission to emit coherent light, in a process that is far from thermal equilibrium. Exciton-polariton condensates -- sharing the same basic device structure as…

We exploit the influence of the Coulomb interaction between electrons and holes on the electron spin relaxation in a (110)-GaAs quantum well to unveil excitonic signatures within the many particle electron-hole system. The temperature…

Mesoscale and Nanoscale Physics · Physics 2011-04-07 S. Oertel , S. Kunz , D. Schuh , W. Wegscheider , J. Hübner , M. Oestreich

We combine linear and non-linear optical spectroscopy at 4K with ab initio calculations to study the electronic bandstructure of MoSe2 monolayers. In 1-photon photoluminescence excitation (PLE) and reflectivity we measure a separation…

Materials Science · Physics 2015-11-05 G. Wang , I. C. Gerber , L. Bouet , D. Lagarde , A. Balocchi , M. Vidal , E. Palleau , T. Amand , X. Marie , B. Urbaszek

Direct experimental evidences for excitonic lasing is obtained in optically pumped V-groove quantum wire structures. We demonstrate that laser emission at a temperature of 10 K arises from a population inversion of localized excitons within…

Materials Science · Physics 2007-05-23 L. Sirigu , D. Y. Oberli , L. Degiorgi , A. Rudra , E. Kapon