(MDPI, 2022) Nicoara, Adrian Ionut; Eftimie, Mihai; Mihail, Elisa; Vasiliu, Ileana Cristina; Bartha, Cristina; Enculescu, Monica; Filipescu, Mihaela; Elosúa Aguado, César; López Torres, Diego; Sava, Bogdan Alexandru; Oane, Mihai; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
IV-VI semiconductor quantum dots embedded into an inorganic matrix represent nanostructured composite materials with potential application in temperature sensor systems. This study
explores the optical, structural, and morphological properties of a novel PbS quantum dots (QDs)-
doped inorganic thin film belonging to the Al2O3
-SiO2
-P2O5 system. The film was synthesized by
the sol-gel method, spin coating technique, starting from a precursor solution deposited on a glass
substrate in a multilayer process, followed by drying of each deposited layer. Crystalline PbS QDs
embedded in the inorganic vitreous host matrix formed a nanocomposite material. Specific investigations such as X-ray diffraction (XRD), optical absorbance in the ultraviolet (UV)-visible (Vis)-near
infrared (NIR) domain, NIR luminescence, Raman spectroscopy, scanning electron microscopy–
energy dispersive X-ray (SEM-EDX), and atomic force microscopy (AFM) were used to obtain a
comprehensive characterization of the deposited film. The dimensions of the PbS nanocrystallite
phase were corroborated by XRD, SEM-EDX, and AFM results. The luminescence band from 1400 nm
follows the luminescence peak of the precursor solution and that of the dopant solution. The emission
of the PbS-doped film in the NIR domain is a premise for potential application in temperature
sensing systems.
