Manufacturing of Volumetric Glass–Based Composites with Single‐ and Double‐QD Doping

Abstract

Quantum dot (QD)‐based light‐emitting materials are gaining increased attention because of their easily tunable optical properties desired for various applications in biology, optoelectronics, and photonics. However, few methods can be used to manufacture volumetric materials doped with more than one type of QD other than QD‐polymer hybrids, and they often require complicated preparation processes and are prone to luminescence quenching by QD aggregation and separation from the matrix. Here, simultaneous doping of a volumetric glass‐based nanocomposite with two types of QDs is demonstrated for the first time in a single‐step process using the nanoparticle direct doping method. Glass rods doped with CdTe, CdSe/ZnS, or co‐doped with both QDs, are obtained. Photoluminescence and lifetime experiments confirm temperature‐dependent double emission with maxima at 596 and 720 nm with mean lifetimes up to 16 ns, as well as radiative energy transfer from the short wavelength–emitting QDs to the long wavelength–emitting QDs. This approach may enable the simple and cost‐efficient manufacturing of bulk materials that produce multicolor luminescence with cascade excitation pumping. Applications that could benefit from this include broadband optical fiber amplifiers, backlight systems in LCD screens, high‐power LEDs, or down‐converting solar concentrators used to increase the efficiency of solar panels.

Functionalization of Phosphate and Tellurite Glasses and Spherical Whispering Gallery Mode Microresonators

“…This result demonstrates that the silanization and bioconjugation may be useful to immobilize antibodies containing primary amines on the surface of easily fabricated phosphate and tellurite glass-based microspheres, especially NAP and TZN-80. The low melting points of these glasses enable easy doping of these materials with optically active nanoparticles using physical methods. − As such, they can act as active lasers for sensitive and selective biosensors in WGM-based sensing devices . These kinds of active WGM resonators are already used in (i) barcode-type cell tagging and tracking and (ii) DNA, , single nanoparticle, and virus detection .…”

“…In this regard, phosphate and tellurite glasses are excellent candidates for fabricating WGM MRs . Low melting points of these glasses enable easy doping with various kinds of optically active elements by using a nanoparticle direct doping method (NPDD). − …”

Light-Generating CdSe/CdS Colloidal Quantum Dot-Doped Plastic Optical Fibers

“…A third nanocomposite fiber category is thus sought to achieve a homogeneous dispersion of cQDs in a solid host material, but, along with minimizing aggregation and surface damage, this remains one of the greatest challenges to cQD doping techniques even in the bulk. ,, Nanocomposite fiber fabrication with cQDs was attempted using either glass or polymer host matrices. In the former case based on a modified chemical vapor deposition (MCVD) process at high temperature, PL emission was not reported and absorption spectra hint that quantum confinement of the unprotected CdSe cores was completely lost. − In the latter case, polymer mixtures with presynthesized nanoparticles are either electrospun − or directly drawn − while the solvent rapidly evaporates at room temperature.…”