Temperature dependence and annealing effects of absorption edges for selenium quantum dots formed by ion implantation in silica glass

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Bibliographic Details
Title: Temperature dependence and annealing effects of absorption edges for selenium quantum dots formed by ion implantation in silica glass
Authors: Ueda, A.1 aueda@fisk.edu, Wu, M.1, Aga, R.1, Meldrum, A.2, White, C.W.3, Collins, W.E.1, Mu, R.1
Source: Surface & Coatings Technology. Aug2007, Vol. 201 Issue 19/20, p8542-8546. 5p.
Subjects: Selenium, Quantum dots, Ion implantation, X-ray diffraction
Abstract: Abstract: We have fabricated Se nanoparticles in silica substrates by ion implantation followed by thermal annealing up to 1000 °C, and studied the Se nanoparticle formation by optical absorption spectroscopy, Rutherford backscattering spectrometry, X-ray diffraction, and transmission electron microscopy. The sample with the highest dose (1×1017 ions/cm2) showed the nanoparticle formation during the ion implantation, while the lower dose samples (1 and 3×1016 ions/cm2) required thermal treatment to obtain nano-sized particles. The Se nanoparticles in silica were found to be amorphous. After thermal annealing, the particle sizes became larger than the exciton Bohr radius for bulk Se. Thus, the absorption edges for different doses approached the value of bulk after thermal annealing. The temperature dependent absorption spectra were also measured for this system in a temperature range from 15 to 300 K. [Copyright &y& Elsevier]
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Database: Engineering Source
Description
Abstract:Abstract: We have fabricated Se nanoparticles in silica substrates by ion implantation followed by thermal annealing up to 1000 °C, and studied the Se nanoparticle formation by optical absorption spectroscopy, Rutherford backscattering spectrometry, X-ray diffraction, and transmission electron microscopy. The sample with the highest dose (1×1017 ions/cm2) showed the nanoparticle formation during the ion implantation, while the lower dose samples (1 and 3×1016 ions/cm2) required thermal treatment to obtain nano-sized particles. The Se nanoparticles in silica were found to be amorphous. After thermal annealing, the particle sizes became larger than the exciton Bohr radius for bulk Se. Thus, the absorption edges for different doses approached the value of bulk after thermal annealing. The temperature dependent absorption spectra were also measured for this system in a temperature range from 15 to 300 K. [Copyright &y& Elsevier]
ISSN:02578972
DOI:10.1016/j.surfcoat.2006.02.074