CdTe QD/Er3+-doped SiO2–Nb2O5 nanocomposites: Thermal, structural and photophysical properties

Abstract CdTe/Er3+-codoped SiO2–Nb2O5-based nanocomposites were prepared by a sol-gel route. The thermal, structural and photophysical properties were investigated by FTIR spectroscopy, N2 adsorption/desorption isotherms, XRD, TGA and DSC analysis, TEM images, UV–Vis spectroscopy, and photoluminescence. The influence of QDs content and niobium/erbium addition on these properties were studied. It is shown that the QDs content into the nanocomposites influences their average size and photoluminescence properties. High QDs content resulted in larger nanocomposite pore size and higher QDs average size. The average pore size created by QDs-doped samples has dimensions suitable for QD adsorption. The TEM images and photoluminescence results demonstrate the successful incorporation of CdTe QDs into the SiO2–Nb2O5 host, which results in a homogeneous nanocomposite material presenting tunable fluorescence in the range of 513–568 nm in function of QD content. Furthermore, CdTe-doped SiO2–Nb2O5-based mesoporous nanocomposite allows the QD chemical stability capped by MPA. These nanocomposites may have a potentially broad application as photonic devices, such as broadband emission devices, optical amplification and lighting.