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1.
Moreels I Fritzinger B Martins JC Hens Z 《Journal of the American Chemical Society》2008,130(45):15081-15086
Solution nuclear magnetic resonance spectroscopy (NMR) is used to identify and quantify the organic capping of colloidal PbSe nanocrystals (Q-PbSe). We find that the capping consists primarily of tightly bound oleic acid ligands. Only a minor part of the ligand shell (0-5% with respect to the number of oleic acid ligands) is composed of tri- n-octylphosphine. As a result, tuning of the Q-PbSe size during synthesis is achieved by varying the oleic acid concentration. By combining the NMR results with inductively coupled plasma mass spectrometry, a complete Q-PbSe structural model of semiconductor core and organic ligands is constructed. The nanocrystals are nonstoichiometric, with a surface that is composed of lead atoms. The absence of surface selenium atoms is in accordance with an oleic acid ligand shell. NMR results on a Q-PbSe suspension, stored under ambient conditions, suggest that oxidation leads to the loss of oleic acid ligands and surface Pb atoms, forming dissolved lead oleate. 相似文献
2.
Aderholz M Aggarwal MM Akbari H Allport PP Badyal SK Ballagh HC Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell JR Cence RJ Chatterjee TK Clayton EF Corrigan G Coutures C DeProspo D Devanand De Wolf EA Faulkner PJ Foeth H Fretter WB Gupta VK Hanlon J Harigel G Harris FA Jabiol MA Jacques P Jain V Jones GT Jones MD Kafka T Kalelkar M Kasper P Kohli JM Koller EL Krawiec RJ Lauko M Lys JE Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J Morrison DR Myatt G Nailor P 《Physical review D: Particles and fields》1992,45(7):2232-2243
3.
Willocq S Aderholz M Akbari H Allport PP Badyal SK Ballagh HC Barth M Bingham HH Brucker EB Burnstein RA Cence RJ Chatterjee TK Clayton EF Corrigan G De Prospo D Devanand De Wolf E Faulkner PJ Foeth H Fretter WB Gupta VK Hanlon J Harigel G Harris FA Jacques P Jain V Jones GT Jones MD Kafka T Kalelkar M Kohli JM Koller EL Krawiec RJ Lauko M Lys JE Marage P Milburn RH Mittra IS Mobayyen MM Moreels J Morrison DR Myatt G Nailor P Naon R Napier A Passmore D Peters MW Peterson VZ Plano R Rao NK 《Physical review D: Particles and fields》1993,47(7):2661-2674
4.
M. Calicchio O. Erriquez M.T. Fogli-Muciaccia S. Natali S. Nuzzo F. Romano F. Ruggieri R. Belusevic D.C. Colley G.T. Jones S. ONeale S.J. Sewell M.F. Votruba D. Bertrand P. Marage J. Moreels J. Sacton F.W. Bullock 《Physics letters. [Part B]》1980,93(4):521-524
An event with the decay chain Σc+ → Λc+ + π0, Λc+ → K? + p + π+, has been observed in an exposure of BEBC, equipped with a track sensitive target, to the wide band neutrino beam from the SPS at CERN. The event has a unique three constraint kinematic fit to the ΔS = ?ΔQ reaction v + p → μ? + p + K? + π+ + π+ + π0 with both gammas from the π0 decay detected. The proton and other final state particles are identified. The masses are M(Λc+) = 2290 ± 3 MeV/c2, M(Σc+) = 2457 ± 4 MeV/c2 and M(Σc+) ? M(Λc+) = 168 ± 3 MeV/c2. Including other data one obtains M (Σc++) ? M(Σc+) = 0 ± 4 MeV/c2. 相似文献
5.
N. Armenise M. Calicchio O. Erriquez M.T. Fogli-Muciaccia S. Natali S. Nuzzo F. Romano R. Belusevic D.C. Colley G.T. Jones S. ONeale S.J. Sewell M.F. Votruba D. Bertrand J. Moreels J. Sacton C. Vander Velde-Wilquet M.A. Parker 《Physics letters. [Part B]》1981,102(5):374-380
Charged-current neutrino interactions have been analysed in a sample of pictures from BEBC equipped with a TST. Using a method independent of both the neutrino flux and nuclear interaction corrections, the ratio R= σn/σp has been measured. The result is R=1.98±0.19 for the ratio of total cross sections. Bjorken x distributions for proton and neutron targets and for u and d quarks are compared. 相似文献
6.
DeProspo D Kalelkar M Aderholz M Akbari H Allport PP Ammosov VV Andryakov A Asratyan A Badyal SK Ballagh HC Baton J Barth M Bingham HH Brucker EB Burnstein RA Cence RJ Chatterjee TK Clayton EF Corrigan G Coutures C Devanand De Wolf E Ermolov P Erofeeva I Faulkner PJ Foeth H Fretter WB Gapienko G Gupta VK Hanlon J Harigel G Harris FA Ivanilov A Jabiol M Jacques P Jain V Jones GT Jones MD Kafka T Kaftanov V Kasper P Kobrin V Kohli JM Koller EL Korablev V Kubantsev M Lauko M Lukina O Lys JE 《Physical review D: Particles and fields》1994,50(11):6691-6703
7.
Lambert K Moreels I Thourhout DV Hens Z 《Langmuir : the ACS journal of surfaces and colloids》2008,24(11):5961-5966
Using InP and PbSe quantum dots, we demonstrate that the Langmuir-Blodgett technique is well-suited to coat nonflat surfaces with quantum dot monolayers. This allows deposition on silicon substrates covered by a developed patterned resist, which results in monolayer patterns with micrometer resolution. Atomic force microscopy and scanning electron microscopy reveal the formation of a densely packed monolayer that replicates predefined structures with high selectivity after photoresist removal. A large variety of shapes can be reproduced and, due to the excellent adhesion of the quantum dots to the substrate, the hybrid approach can be repeated on the same substrate. This final possibility leads to complex, large-area quantum dot monolayer structures with micrometer spatial resolution that may combine different types of quantum dots. 相似文献
8.
A spectroscopic study of the optical non-linearities of PbSe colloidal solutions was performed with the Z-scan technique, at wavelengths between 1200 and 1750 nm. No non-linear absorption is observed, while the third-order non-linear refractive index n2 shows clear resonances, somewhat blueshifted relative to the exciton transitions in the absorbance spectrum. The occurrence of thermal effects is ruled out by time-resolved measurements. At resonance, measured n2 values exceed typical bulk semiconductor values by two orders of magnitude. At high optical intensity, the refractive index change saturates, indicating that state filling lies at the origin of the observed effect. 相似文献
9.
Lambert K Wittebrood L Moreels I Deresmes D Grandidier B Hens Z 《Journal of colloid and interface science》2006,300(2):597-602
We demonstrate the organization of nearly monodisperse colloidal InP quantum dots at the air/water interface in Langmuir monolayers. The organization of the particles is monitored in situ by surface pressure-surface area measurements and ex situ by AFM measurements on films transferred to mica by Langmuir-Blodgett deposition. The influence of different ligands on the quality of the monolayer formed has been studied. We show that densely packed monolayers with little holes can be formed using short chain ligands like pyridine and pentamethylene sulfide. The advantage of using short chain ligands for electron tunneling to or from the quantum dots is demonstrated using scanning tunneling spectroscopy. 相似文献
10.
Aderholz M Aggarwal MM Akbari H Allport PP Baba PV Badyal SK Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell RC Cence R Chatterjee TK Clayton EF Corrigan G Coutures C De Prospo D Devanand De Wolf E Faulkner PJ Fretter WB Gupta VK Guy J Hanlon J Harigel G Harris F Jabiol MA Jacques P Jain V Jones GT Jones MD Jones RW Kafka T Kalelkar M Kasper P Kaul GL Kaur M Kohli JM Koller EL Krawiec RJ Lauko M Lys J Mann WA Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J 《Physical review letters》1989,63(21):2349-2352