Confined quantum dots in nanoporous glass matrices for tunable photoluminescence and optoelectronic applications

Abstract

Integrating quantum dots (QDs) into glass matrices has drawn extensive attention, as it enhances the stability of QDs with improved optical characteristics and facilitates their wide and durable application in photonics devices. Currently, QD-embedded glasses are commonly prepared by the heat treatment of melt-quenching-derived dense glasses, limiting control of the precise size and emission of the QDs due to the high-temperature process and structural rigidity within dense glasses. Herein, we report a room-temperature gas-phase diffusion strategy utilizing the rigid nanopores of sol–gel derived glasses as templates to strictly confine the growth of QDs. This allows control over the growth and photoluminescence of PbS QDs in the near-infrared range (1176–1356 nm) and CdS QDs in the visible range (587–689 nm) solely by tuning the glass pore size. The growth mechanism of the QDs in the nano-confined space was investigated, revealing a rapid size increase and spectral redshift for the QDs during the initial reaction stage, followed by stabilization in both size and photoluminescence, which was attributed to the nano-confinement effect. Notably, the presence of interfacial chemical interactions between the QDs and glass matrices was revealed by X-ray absorption fine structure and X-ray photoelectron spectroscopy analyses. Moreover, the application of CdS QD glass in white light-emitting diode (LED) devices and the photocatalytic degradation of dyes is demonstrated, highlighting key ways to manufacture durable, advanced optical devices and achieve the goal of environmental remediation.