15 research outputs found
Defect-free ZnSe nanowire and nano-needle nanostructures
We report on the growth of ZnSe nanowires and nano-needles using molecular
beam epitaxy (MBE). Different growth regimes were found, depending on growth
temperature and the Zn--Se flux ratio. By employing a combined MBE growth of
nanowires and nano-needles without any post-processing of the sample, we
achieved an efficient suppression of stacking fault defects. This is confirmed
by transmission electron microscopy and by photoluminescence studies.Comment: 4 pages, 4 figure
Photon correlation spectroscopy on a single quantum dot embedded in a nanowire
We have observed strong photoluminescence from a single CdSe quantum dot
embedded in a ZnSe nanowire. Exciton, biexciton and charged exciton lines have
been identified unambiguously using photon correlation spectroscopy. This
technique has provided a detailed picture of the dynamics of this new system.
This type of semi conducting quantum dot turns out to be a very efficient
single photon source in the visible. Its particular growth technique opens new
possibilities as compared to the usual self-asssembled quantum dots
Dark exciton optical spectroscopy of a semiconducting quantum dot embedded in a nanowire
Photoluminescence of a single CdSe quantum dot embedded in a ZnSe nanowire has been investigated. It has been found that the dark exciton has a strong influence on the optical properties. The most visible influence is the strongly reduced excitonic emission compared to the biexcitonic one. Temperature dependent lifetime measurements have allowed us to measure a large splitting of meV between the dark and the bright exciton as well as the spin flip rates between these two states
CdSe quantum dot in a ZnSe nanowire as an efficient source of single photons
International audienceWe report on our development of fabrication of CdSe QD in ZnSe nanowire. We have been able to obtain high quality structures with very good optical properties. This has allowed us to measure photon emission from single quantum dots and to demonstrate photon antibunching. We show that this new type of II-VI quantum dot is very promising for high temperature operation
Single photons from single CdSe quantum dot embedded in ZnSe nanowire
International audienceWe report the growth of ZnSe nanowires and nanoneedles using molecular beam epitaxy (MBE). Different growth regimes were found, depending oil growth temperature and the Zn-Se flux ratio. By employing a combined MBE growth of nanowires and nanoneedles Without ally postprocessing of the sample, we achieved an efficient Suppression of stacking fault defects. This is confirmed by transmission electron microscopy and by photoluminescence studies. We have inserted a single CdSe quantum dot ill these nanowires and we have observed Strong photoluminescence from a single CdSe quantum dot embedded in a ZnSe nanowire. Exciton, biexciton and charged exciton lines have been identified Unambiguously using photon correlation spectroscopy. This technique has provided a detailed picture of the dynamics of this new system. This type of semi-conducting quantum dot turns out to be a very efficient single photon Source in the visible ill a temperature as high as 220 K. Its particular growth technique opens new possibilities as compared to the usual self-asssembled quantum dot
Bright CdSe quantum dot inserted in single ZnSe nanowires
International audienceWe report the evidence of CdSe quantum dot (QD) insertion in single defect-free ZnSe nanowire. These nanowires have been grown by molecular beam epitaxy in vapour-liquid-solid growth mode catalysed with gold particles. We developed a two-step process allowing us to grow very thin (from 15 to 5 nm) defect-free ZnSe nanowire on top of a nanoneedle, where all defects are localised. The CdSe QDs are incorporated to the defect-free nanowires part. Owing to the extraction efficiency of the nanowires and the reduced number of stacking fault defects in the two-step-process nanowires, a very efficient photoluminescence is observed even on isolated single nanowire. Time-resolved photoluminescence and correlation photon give evidences that the bright photon emission is related to the CdSe Q
Opioid-sparing strategies and their link to postoperative morphine and antiemetic administration: a retrospective study
International audienc
Growth and properties of defect-free ZnSe nanowires and nanoneedles
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