@article {Abderrafi:2012:1533-4880:6774,
title = "Production of Nanometer-Size GaAs Nanocristals by Nanosecond Laser Ablation in Liquid",
journal = "Journal of Nanoscience and Nanotechnology",
parent_itemid = "infobike://asp/jnn",
publishercode ="asp",
year = "2012",
volume = "12",
number = "8",
publication date ="2012-08-01T00:00:00",
pages = "6774-6778",
itemtype = "ARTICLE",
issn = "1533-4880",
eissn = "1533-4899",
url = "https://www.ingentaconnect.com/content/asp/jnn/2012/00000012/00000008/art00103",
doi = "doi:10.1166/jnn.2012.4548",
author = "Abderrafi, Kamal and Jim{\’e}nez, Ernesto and Ben, Teresa and Molina, Sergio I. and Ib{\’a}{\~n}ez, Rafael and Chirvony, Vladimir and Mart{\’ı}nez-Pastor, Juan P.",
abstract = "This paper reports the formation and characterization of spherical GaAs quantum dots obtained by nanosecond pulsed laser ablation in a liquid (ethanol or methanol). The produced bare GaAs nanoparticles demonstrate rather narrow size distribution which depends on the applied laser power
density (from 4.25 to 13.9 J/cm2 in our experiments) and is as low as 2.5 nm for the highest power used. The absolute value of the average diameter also decreases significantly, from 13.7 to 8.7 nm, as the laser power increases in this interval. Due to the narrow nanoparticle size
dispersion achieved at the highest laser powers two absorption band edges are clearly distinguishable at about 1.72 and 3.15 eV which are ascribed to E0 and E1 effective optical transitions, respectively. A comparison of the energies with those known for bulk GaAs allows one
to conclude that an average diameter of the investigated GaAs nanoparticles is close to 10 nm, i.e., they are quantum dots. High resolution transmission electron microscopy (HRTEM) images show that the bare GaAs nanoparticles are nanocrystalline, but many of them exhibit single/multiple twin
boundary defects or even polycrystallinity. The formation of the GaAs crystalline core capped with a SiO2 shell was demonstrated by HRTEM and energy dispersive X-ray (EDX) spectroscopy. Effective band edges can be better distinguished in SiO2 capped nanoparticles than
in bare ones, In both cases the band edges are correlated with size quantum confinement effect.",
}