Available online at www.sciencedirect.com Journal of Applied Research and Technology www.jart.ccadet.unam.mx Journal of Applied Research and Technology 13 (2015) 566–575 Original Fabrication and photophysical studies of CdTe quantum-dots dispersed in SiO 2 sonogel optical-glasses Omar G. Morales-Saavedra a,∗ , Claudio D. Gutiérrez-Lazos b , Mauricio Ortega-López c , Antonio A. Rodriguez-Rosales a a Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Apartado Postal 70-186, México D.F. 04510, Mexico b Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, 66451 San Nicolás de los Garza, NL, Mexico c Departamento de Ingeniería Eléctrica, Sección de Electrónica del Estado Sólido, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360 México D.F., Mexico Received 21 April 2015; accepted 22 September 2015 Available online 28 November 2015 Abstract The catalyst-free sonogel route has been implemented to fabricate highly pure SiO 2 glasses as host materials for CdTe quantum dot nanocrystals synthesized in aqueous solution. Developed CdTe-based inorganic–inorganic hybrid composites exhibited rigid bulk structures with controllable geometrical shapes and dopant concentrations, allowing the control of the optical properties in the solid-state confinement. Comprehensive linear and nonlinear photophysical characterizations were performed according to UV–vis absorbance, Raman and photoluminescent spectroscopies; the linear refractive indices of highly/lowly CdTe-doped samples were also estimated according to the Brewster angle technique. Since the hybrid glasses are amorphous in nature, the cubic nonlinear optical activity of these composites has been tested via the Z-Scan technique. Results show that the CdTe quantum dots were homogeneously embedded within the SiO 2 -sonogel matrix with only small guest–host molecular interactions and preserving their strong photoluminescent properties; thus providing advanced solid-state heterostructured nanocomposite materials suitable for current technological photonic applications. All Rights Reserved © 2015 Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico. This is an open access item distributed under the Creative Commons CC License BY-NC-ND 4.0. Keywords: Cadmium telluride; Quantum dot; Spectroscopy; Nonlinear optics; Hybrid material; Sol–gel 1. Introduction Inorganic semiconductor nanocrystals (NCs) or quantum dots (QDs) exhibit physical and chemical properties which consid- erably differ from their individual molecules or bulk forms, due to quantum confinement effects (Kagan, Murray, & Bawendi, 1996; Rogach et al., 2007). These properties have a huge interest for applications in optoelectronics (Gao et al., 2000; Hollingsworth et al., 2001; Schlamp, Peng, & Alivisatos, 1997), photovoltaic devices (Huang, De Valle, Kana, Simmons-Potter, & Potter, 2015; Rajbanshi, Sarkar, & Sarkar, 2014; Sehgal & Narula, 2015), optical amplifier media for telecommunication networks (Harrison et al., 2000), and biolabeling/biomedical ∗ Corresponding author. E-mail address: omar.morales@ccadet.unam.mx (O.G. Morales-Saavedra). Peer Review under the responsibility of Universidad Nacional Autónoma de México. devices (Chao, Hu, & Chen, 2014; Gao, Cui, Levenson, Chung, & Nie, 2004). A relatively recent approach to realize elec- troluminescent devices has emerged from the development of colloidal quantum dots, because they can be synthesized in organic solvents (Murray, Norris, & Bawendi, 1993) or water (Gaponik et al., 2002a; Gaponik, Talapin, Rogach, Eychmüller, & Weller, 2002b). Besides, the nanocrystals surface can be con- veniently functionalized to transfer it from water to an organic solvent (Gaponik et al., 2002a, 2002b) or vice versa, depend- ing if a given application requires the use of polar or apolar solvents. The nanocrystals physicochemical properties strongly depend on the surface characteristics as the nanoparticle size is reduced below the Bohr exciton diameter; this is due to its very high surface/volume ratio. Therefore, the nanocrystals surface must be functionalized in order to activate the optical properties; for instance, luminescence. In a colloidal solution, nanocrystals are protected against aggregation by an organic capping layer http://dx.doi.org/10.1016/j.jart.2015.10.013 1665-6423/All Rights Reserved © 2015 Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico. This is an open access item distributed under the Creative Commons CC License BY-NC-ND 4.0.