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.