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Title: Determination of absorption cross-section of Si nanocrystals by two independent methods based on either absorption or luminescence

Absorption cross-section (ACS) of silicon nanocrystals (SiNCs) is determined via two completely independent approaches: (i) Excitation-intensity-dependent photoluminescence (PL) kinetics under modulated (long square pulses) pumping and (ii) absorbance measured by the photothermal deflection spectroscopy combined with morphology information obtained by the high-resolution transmission electron microscopy. This unique comparison reveals consistent ACS values around 10{sup −15} cm{sup 2} for violet excitation of SiNCs of about 3–5 nm in diameter and this value is comparable to most of direct band-gap semiconductor nanocrystals; however, it decreases steeply towards longer wavelengths. Moreover, we analyze the PL-modulation technique in detail and propose an improved experimental procedure which enables simpler implementation of this method to determine ACS of various (nano)materials in both solid and liquid states.
Authors:
;  [1] ;  [2] ; ; ;  [3]
  1. Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic)
  2. Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, Prague 6 (Czech Republic)
  3. Faculty of Engineering, IMTEK, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany)
Publication Date:
OSTI Identifier:
22489297
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 2; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; CROSS SECTIONS; EXCITATION; MORPHOLOGY; NANOSTRUCTURES; PHOTOLUMINESCENCE; SEMICONDUCTOR MATERIALS; SILICON; TRANSMISSION ELECTRON MICROSCOPY; WAVELENGTHS