CONICET | Buscador de Institutos y Recursos Humanos

Building a device based on the unique properties of nanoparticles (NPs), such as their size dependent optical response usually requires a substrate. On the other hand, most of semiconductor Q-dots proven to have absorption and luminescence tuned by their size are extremely toxic. A proposed solution to these problems is the encapsulation of NPs in an inert matrix. However, the resulting composite material, Q-dot@SiO2, must be stable and robust, maintaining the desired properties for long terms, and when needed the surface of Q-dots must be exposed to the surrounding medium. In addition, the synthesis pathway requires good reproducibility. Here, we present the optical response of CdX (X = S, Se) and Bi2S3 embedded in SiO2 mesoporous (MP) films with regular structure, which is defined by the amphiphilic employed for their synthesis. The encapsulated Q-dots are synthesized inside pores by reaction between the metallic precursor and the chalcogenide. The optical response of embedded Q-dots is controlled by the size of pores and is comparable to that of Q-dot colloids; even the emission band is wider when NPs are encapsulated. The preparation method for each Q-dot@SiO2 is highly reproducible, and we found a stable optical response for several months, longer than that found for their respective colloids.

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