Photoluminescent Sol-Gel Glass Constructed via Highly Efficient Förster Resonance Energy Transfer

Abstract

Photoluminescent (PL) solid with color tunability are in high demand for the development of large-area display and illumination devices. With high transparency, high chemical stability, and mature fabrication, sol-gel glass is an ideal solid matrix to obtain such materials by chromophore doping. However, it remains a big challenge to obtain sol-gel glass with high luminous efficiency under a single excitation wavelength. Herein, the construction of highly luminescent sol-gel glass enabled by Förster resonance energy transfer (FRET) is reported. Branched siloxane is used to modify naphthalene and BODIPY, which led to the formation of blue-emitting donor (denoted as Si-Nap) and green-emitting acceptor (denoted as Si-BODIPY), respectively. Efficient FRET occurs between Si-Nap and Si-BODIPY proved by spectral titration and lifetime measurements, with an energy transfer efficiency (Φ_ET) up to 97.9%. When RhB is added, it acts as a final acceptor that enables the occurrence of a sequential FRET from Si-Nap to Si-BODIPY and further to RhB. The overall energy transfer efficiency reaches 94%, and the fluorescence quantum yield exceeds 88%. By adjustment of the composition, color-tunable sol-gel glass is obtained with emergence of white-emitting samples, opening potential applications in a variety of fields.