Excitation-Dependent Multicolour Luminescence of Organic Materials: Internal Mechanism and Potential Applications

Excitation-dependent emission (Ex-de) materials have been of considerable academic interest and have potential applications in real life. Such multicolour luminescence is a characteristic exception to the ubiquitously accepted Kasha's rule. This phenomenon has been increasingly presented in some studies on different luminescence systems; however, a systematic overview of the mechanisms underlying this phenomenon is currently absent. Herein, we resolve this issue by classifying multicolour luminescence from single chromophores and dual/ternary chromophores, as well as multiple emitting species. The underlying processes are described based on electronic and/or geometrical conditions under which the phenomenon occurs. Before we present it in categories, related photophysical and photochemical foundations are introduced. This systematic overview will provide a clear approach to designing multicolour luminescence materials for special applications.

Automated summary

This paper provides a systematic overview of the phenomenon of multicolour luminescence, classifying it based on single chromophores, dual/ternary chromophores, and multiple emitting species. The underlying processes are described, taking into account the electronic and/or geometrical conditions under which the phenomenon occurs. Related photophysical and photochemical foundations are also introduced, providing a clear approach to designing multicolour luminescence materials for special applications.