Recent Advances on Molecular Crystalline Luminescent Materials for Optical Waveguides

Abstract Molecule‐based fluorescent materials with optical waveguides (MFOWs) have attracted great research interest in the optoelectronic and photonic fields due to their unique photoluminescence properties. Theoretically, the waveband of propagated light within the MFOWs can cover the entire visible light region, which has been one of the important branches in micro/nanophotonics. In this review, the research progress of MFOWs during the last few years, including the basic emission parameters, waveguiding mechanisms, and design methods including adjustments of size, dimension, and shape at the micro/nano‐scales is systematically summarized. New emerging materials (such as flexible nanostructures, molecular cocrystals, and organic–inorganic hybrids) are described towards the high‐performance MFOWs applications. Although tremendous researches for developing MFOWs have been conducted, there remain several dilemmas, such as the deep understanding on elucidated mechanisms and the difficulty for commercialization. Thus, this work also presents the existing challenges and insightful trends, which offer potential guidance for the design and development of MFOWs in future.