Laser-induced photodynamic effects at silica nanocomposite based on cadmium sulphide quantum dots S. S. Voznesenskiy,1 A. A. Sergeev,1* A. N. Galkina,1 Yu. N. Kulchin,1 Yu. A. Shchipunov,2 and I. V. Postnova2 1 2
Institute of Automation and Control Processes Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia Institute of Chemistry Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia, USA * [email protected]
Abstract: In this paper we study the laser-induced modification of optical properties of nanocomposite based on cadmium sulphide quantum dots encapsulated into thiomalic acid shell which were embedded into a porous silica matrix. We found red shift of luminescence of the nanocomposite when exposed to laser radiation at λ = 405 nm. Using pump-probe method and Small-Angle X-ray Scattering technique it was found that laser radiation at λ = 405 nm also increases the absorption coefficient of the nanocomposite in 15 times due to agglomeration of quantum dots. The modification of absorption properties is fully reversible. ©2014 Optical Society of America OCIS codes: (230.1150) All-optical devices; (230.5590) Quantum-well, -wire and -dot devices.
References and links 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
K. M. Dani, Z. Ku, P. C. Upadhya, R. P. Prasankumar, A. J. Taylor, and S. R. J. Brueck, “Ultrafast nonlinear optical spectroscopy of a dual-band negative index metamaterial all-optical switching device,” Opt. Express 19(5), 3973–3983 (2011). U. Wiedemann, W. Alt, and D. Meschede, “Switching photochromic molecules adsorbed on optical microfibres,” Opt. Express 20(12), 12710–12720 (2012). Y. Huang, S.-T. Wu, and Y. Zhao, “All-optical switching characteristics in bacteriorhodopsin and its applications in integrated optics,” Opt. Express 12(5), 895–906 (2004). S. Ren, L.-Y. Chang, S.-K. Lim, J. Zhao, M. Smith, N. Zhao, V. Bulović, M. Bawendi, and S. Gradecak, “Inorganic-organic hybrid solar cell: bridging quantum dots to conjugated polymer nanowires,” Nano Lett. 11(9), 3998–4002 (2011). H. M. Gong, X.-H. Wang, Y. M. Du, and Q. Q. Wang, “Optical nonlinear absorption and refraction of CdS and CdS-Ag core-shell quantum dots,” J. Chem. Phys. 125(2), 024707 (2006). D. Bera, L. Qian, T.-K. Tseng, and P. H. Holloway, “Quantum dots and their multimodal applications: A review,” Materials. 3(4), 2260–2345 (2010). K. M. Sergeeva, I. V. Postnova, and Yu. A. Shchipunov, “Incorporation of Quantum Dots into a Silica matrix using a compatible precursor,” Colloid J. 75(6), 714–719 (2013). Q. Xiao and C. Xiao, “Surface-defect-states photoluminescence in CdS nanocrystals prepared by one-step aqueous synthesis method,” Appl. Surf. Sci. 255(16), 7111–7114 (2009). E. Ruiz-Hitzky, K. Ariga, and Yu. M. Lvov, Bio-inorganic Hybrid Nanomaterials (Weinheim, 2007), Chap. 3. L. A. Feigin and D. I. Svergun, Structure Analysis by Small-Angle X-ray and Neutron Scattering, G.W. Taylor, ed. (Plenum Press, 1987). P. V. Konarev, V. V. Volkov, A. V. Sokolova, M. H. J. Koch, and D. I. Svergun, “PRIMUS: a Windows PCbased system for small-angle scattering data analysis,” J. Appl. Cryst. 36(5), 1277–1282 (2003). D. I. Svergun, “Determination of the regularization parameter in indirect-transform methods using perceptual criteria,” J. Appl. Cryst. 25(4), 495–503 (1992). D. I. Svergun, “Restoring low resolution structure of biological macromolecules from solution scattering using simulated annealing,” Biophys. J. 76(6), 2879–2886 (1999). J. Tang and R. A. Marcus, “Photoinduced spectral diffusion and diffusion-controlled electron transfer reactions in fluorescence intermittency of quantum dots,” J. Chin. Chem. Soc. 53, 1–13 (2006). A. Tang, F. Teng, Y. Hou, Y. Wang, F. Tan, S. Qu, and Z. Wang, “Optical properties and electrical bistability of CdS nanoparticles synthesized in dodecanethiol,” Appl. Phys. Lett. 96(16), 163112 (2010). J. S. Jie, W. J. Zhang, Y. Jiang, X. M. Meng, Y. Q. Li, and S. T. Lee, “Photoconductive characteristics of singlecrystal CdS nanoribbons,” Nano Lett. 6(9), 1887–1892 (2006).
#200167 - $15.00 USD (C) 2014 OSA
Received 28 Oct 2013; revised 25 Dec 2013; accepted 14 Jan 2014; published 24 Jan 2014 27 January 2014 | Vol. 22, No. 2 | DOI:10.1364/OE.22.002105 | OPTICS EXPRESS 2105
1. Introduction All-optical devices are extensively used for photonic applications such as processing and storage of large capacity information [1]. The most investigated nonlinear optical effect which is necessary for developing such devices is the process for control the radiation power of one wavelength by radiation power of another wavelength (so-called optical switching) [2, 3]. In this case, the radiation with shorter wavelength is used as a pump, and other radiation is a probe. Pump radiation modifies the optical properties of a sample, namely refractive index and/or absorption coefficient. Commonly, probe radiation does not alter the optical properties of the sample, and used only as a scanning radiation [1, 3]. The development of optical switching devices is basically associated with the use of photochromic materials as an active medium [2, 3]. Such approach has a significant drawback due to degradation of the active medium under prolonged exposure of pump radiation [2]. To date the scientific attention is given to nonlinear optical nanocomposite materials based on quantum dots (QD) incorporated into organic shell. These materials are unique in that they manifest different properties (such as photoconductivity, optical bistability, photorefraction) simultaneously as well as they have significant photo and chemical stability compared to photochromic materials [4]. Well studied luminescent properties [5] and electronic structure of CdS QD [6] as well as the mentioned above opto-electronical properties allow us to conclude that these QDs are promising for photonic application, particularly optical switcher. Therefore, in this paper we study the laser-induced optical switching effect in the nanocomposite based on CdS QD (hereinafter - NcQD) stabilized by thiomalic acid shell and incorporated into a porous silica matrix THEOS (Tetrakis (2- hydroxyethyl) orthosilicate) [7]. 2. Materials and methods Synthesis of QD was performed by methods proposed in [8]. THEOS was synthesized by the method described in [9]. QD stabilized by thiomalic acid were dispersed in deionized water with concentration of 0.3 wt. %. After that THEOS was added in stabilized solution of QD under vigorous stirring. The obtained nanocomposite was poured into a flat cuvette with thickness of 1 mm. The structural studies of nanocomposite were carried out using the small angle X-ray diffractometer SAXS («HECUS», Austria). The experimental scattering curves were obtained at wavelength λ = 0.1542 nm in the range of wave vectors 0.07
Institute of Automation and Control Processes Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia Institute of Chemistry Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia, USA * [email protected]
Abstract: In this paper we study the laser-induced modification of optical properties of nanocomposite based on cadmium sulphide quantum dots encapsulated into thiomalic acid shell which were embedded into a porous silica matrix. We found red shift of luminescence of the nanocomposite when exposed to laser radiation at λ = 405 nm. Using pump-probe method and Small-Angle X-ray Scattering technique it was found that laser radiation at λ = 405 nm also increases the absorption coefficient of the nanocomposite in 15 times due to agglomeration of quantum dots. The modification of absorption properties is fully reversible. ©2014 Optical Society of America OCIS codes: (230.1150) All-optical devices; (230.5590) Quantum-well, -wire and -dot devices.
References and links 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
K. M. Dani, Z. Ku, P. C. Upadhya, R. P. Prasankumar, A. J. Taylor, and S. R. J. Brueck, “Ultrafast nonlinear optical spectroscopy of a dual-band negative index metamaterial all-optical switching device,” Opt. Express 19(5), 3973–3983 (2011). U. Wiedemann, W. Alt, and D. Meschede, “Switching photochromic molecules adsorbed on optical microfibres,” Opt. Express 20(12), 12710–12720 (2012). Y. Huang, S.-T. Wu, and Y. Zhao, “All-optical switching characteristics in bacteriorhodopsin and its applications in integrated optics,” Opt. Express 12(5), 895–906 (2004). S. Ren, L.-Y. Chang, S.-K. Lim, J. Zhao, M. Smith, N. Zhao, V. Bulović, M. Bawendi, and S. Gradecak, “Inorganic-organic hybrid solar cell: bridging quantum dots to conjugated polymer nanowires,” Nano Lett. 11(9), 3998–4002 (2011). H. M. Gong, X.-H. Wang, Y. M. Du, and Q. Q. Wang, “Optical nonlinear absorption and refraction of CdS and CdS-Ag core-shell quantum dots,” J. Chem. Phys. 125(2), 024707 (2006). D. Bera, L. Qian, T.-K. Tseng, and P. H. Holloway, “Quantum dots and their multimodal applications: A review,” Materials. 3(4), 2260–2345 (2010). K. M. Sergeeva, I. V. Postnova, and Yu. A. Shchipunov, “Incorporation of Quantum Dots into a Silica matrix using a compatible precursor,” Colloid J. 75(6), 714–719 (2013). Q. Xiao and C. Xiao, “Surface-defect-states photoluminescence in CdS nanocrystals prepared by one-step aqueous synthesis method,” Appl. Surf. Sci. 255(16), 7111–7114 (2009). E. Ruiz-Hitzky, K. Ariga, and Yu. M. Lvov, Bio-inorganic Hybrid Nanomaterials (Weinheim, 2007), Chap. 3. L. A. Feigin and D. I. Svergun, Structure Analysis by Small-Angle X-ray and Neutron Scattering, G.W. Taylor, ed. (Plenum Press, 1987). P. V. Konarev, V. V. Volkov, A. V. Sokolova, M. H. J. Koch, and D. I. Svergun, “PRIMUS: a Windows PCbased system for small-angle scattering data analysis,” J. Appl. Cryst. 36(5), 1277–1282 (2003). D. I. Svergun, “Determination of the regularization parameter in indirect-transform methods using perceptual criteria,” J. Appl. Cryst. 25(4), 495–503 (1992). D. I. Svergun, “Restoring low resolution structure of biological macromolecules from solution scattering using simulated annealing,” Biophys. J. 76(6), 2879–2886 (1999). J. Tang and R. A. Marcus, “Photoinduced spectral diffusion and diffusion-controlled electron transfer reactions in fluorescence intermittency of quantum dots,” J. Chin. Chem. Soc. 53, 1–13 (2006). A. Tang, F. Teng, Y. Hou, Y. Wang, F. Tan, S. Qu, and Z. Wang, “Optical properties and electrical bistability of CdS nanoparticles synthesized in dodecanethiol,” Appl. Phys. Lett. 96(16), 163112 (2010). J. S. Jie, W. J. Zhang, Y. Jiang, X. M. Meng, Y. Q. Li, and S. T. Lee, “Photoconductive characteristics of singlecrystal CdS nanoribbons,” Nano Lett. 6(9), 1887–1892 (2006).
#200167 - $15.00 USD (C) 2014 OSA
Received 28 Oct 2013; revised 25 Dec 2013; accepted 14 Jan 2014; published 24 Jan 2014 27 January 2014 | Vol. 22, No. 2 | DOI:10.1364/OE.22.002105 | OPTICS EXPRESS 2105
1. Introduction All-optical devices are extensively used for photonic applications such as processing and storage of large capacity information [1]. The most investigated nonlinear optical effect which is necessary for developing such devices is the process for control the radiation power of one wavelength by radiation power of another wavelength (so-called optical switching) [2, 3]. In this case, the radiation with shorter wavelength is used as a pump, and other radiation is a probe. Pump radiation modifies the optical properties of a sample, namely refractive index and/or absorption coefficient. Commonly, probe radiation does not alter the optical properties of the sample, and used only as a scanning radiation [1, 3]. The development of optical switching devices is basically associated with the use of photochromic materials as an active medium [2, 3]. Such approach has a significant drawback due to degradation of the active medium under prolonged exposure of pump radiation [2]. To date the scientific attention is given to nonlinear optical nanocomposite materials based on quantum dots (QD) incorporated into organic shell. These materials are unique in that they manifest different properties (such as photoconductivity, optical bistability, photorefraction) simultaneously as well as they have significant photo and chemical stability compared to photochromic materials [4]. Well studied luminescent properties [5] and electronic structure of CdS QD [6] as well as the mentioned above opto-electronical properties allow us to conclude that these QDs are promising for photonic application, particularly optical switcher. Therefore, in this paper we study the laser-induced optical switching effect in the nanocomposite based on CdS QD (hereinafter - NcQD) stabilized by thiomalic acid shell and incorporated into a porous silica matrix THEOS (Tetrakis (2- hydroxyethyl) orthosilicate) [7]. 2. Materials and methods Synthesis of QD was performed by methods proposed in [8]. THEOS was synthesized by the method described in [9]. QD stabilized by thiomalic acid were dispersed in deionized water with concentration of 0.3 wt. %. After that THEOS was added in stabilized solution of QD under vigorous stirring. The obtained nanocomposite was poured into a flat cuvette with thickness of 1 mm. The structural studies of nanocomposite were carried out using the small angle X-ray diffractometer SAXS («HECUS», Austria). The experimental scattering curves were obtained at wavelength λ = 0.1542 nm in the range of wave vectors 0.07
