Available online at www.sciencedirect.com ScienceDirect Physics Procedia 86 (2017) 11 – 14 International Conference on Photonics of Nano- and Bio-Structures, PNBS-2015, 19-20 June 2015, Vladivostok, Russia and the International Conference on Photonics of Nano- and MicroStructures, PNMS-2015, 7-11 September 2015, Tomsk, Russia Modification of optical properties of CdS-silicate nanocomposites by thermal annealing A.A Sergeeva,b*, S.S Voznesenskiya,b,A.N Galkinaa, I.V Postnovab a Institute of Automation and Control Processes of FEB RAS, Radio St., Vladivostok 690041, Russia b Far Eastern Federal University, 8, Sukhanova St., Vladivostok 690950, Russia Abstract Temperature influence on optical and structural properties of nanocomposite structures based on cadmium sulfide quantum dots in silicate matrix was investigated The mechanism of occurrence of reversible laser-induced absorption is proposed It was found that annealing of nanocomposite up to 120 °C leads to substantial change of its absorption and luminescence spectra caused by transformation of quantum dot crystal lattice from amorphous to sphalerite The nanocomposite with the sphalerite lattice QDs does not possess the effect of the photo-induced absorption ©2017 2016The TheAuthors Authors Published by Elsevier © Published by Elsevier B.V B.V This is an open access article under the CC BY-NC-ND license Peer-review under responsibility of the organizing committee of PNBS-2015 and PNMS-2015 (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of PNBS-2015 and PNMS-2015 Keywords: quantum dots; cadmium sulphide; thermal ammealing; luminescence; absorption Introduction In previous works (Voznesenskiy S.S et al (2014), Voznesenskiy S.S et al (2015)) laser radiation influence on nanocomposite formed by cadmium sulfide quantum dots (QDs) embedded in porous sol-gel matrix was discussed It was found that laser excitation at wavelength less than 470 nm gave rise to absorption coefficient and red shifted the luminescence maximum of naocomposite The reversible laser-induced optical absorption effect was defined as an increase in absorption coefficient value under laser exposure at Ȝ = 405.9 nm When the excitation stopped, the * Corresponding author Tel.: +7-423-231-75-95; fax: +7-423-231-04-52 E-mail address: Sergeev@iacp.dvo.ru 1875-3892 © 2017 The Authors Published by Elsevier B.V This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the organizing committee of PNBS-2015 and PNMS-2015 doi:10.1016/j.phpro.2017.01.003 12 A.A Sergeev et al / Physics Procedia 86 (2017) 11 – 14 value of the absorption coefficient returned to initial level Results obtained clearly demonstrated occurrence of reversible structural changes in the nanocomposite under laser radiation However, the mechanism of laser-induced absorption arising is not absolutely clear yet Materials and methods CdS-silicate nanocomposite was synthesized by means of technique suggested in (Sergeeva K.M et al (2013)) Thermal annealing of obtained nanocomposite was performed in thermostatical muffle furnace for 15 hours Temperature fluctuation during annealing process did not exceed 1% Absorption and luminescence spectra were registrated both immediately after annealing and after cooling of samples to room temperature The absence of differences in spectra testifies about stability of observed effects Studies of photo-induced absorption were carried out by “pump&probe” technique on experimental device described in (Wiedemann U et al (2012)) Structural features of the nanocomposite were studied by Small and Wide angle X-ray scattering (SWAXS) system Hecus S3-MICRO (Hecus X-Ray Systems GmbH, Austria) Experimental scattering intensity was measured in the range of wave vectors of 0.07