ConspectusSmart materials capable of in situ self-responding to external stimuli are proliferating due to their promising properties for advanced applications, including liquid crystal displays, information encryption, visual sensing, and substance detections. Significant progress has been made in designing and developing novel smart materials ranging from memory polymers to phase-change materials, color-change materials, etc. Inspired by these advances, the integration of intelligent functional groups into organic semiconductors offers a promising path to endow optoelectronic materials with selectively adaptive and dynamic features. This integration enables real-time, controllable, and repeatable responses to environmental changes, which allows optoelectronic materials to dynamically adjust their properties during processes such as carrier transport, energy transfer, and radiative/nonradiative exciton decay in device operation for achieving enhanced device performance. However, the development of intelligent structures remains challenging, and the lack of rational strategies for effectively integrating these structures with functional building blocks continues to impede the progress of smart optoelectronic materials.In this Account, a concise, universal, and effective tactic, called resonance variation-based dynamic adaptation (RVDA), to design and construct smart organic optoelectronic materials by incorporating resonance structures into organic building blocks has been proposed. RVDA materials through facile interconversion between canonical forms enable significant enhancement of optoelectronic properties through dynamic modulation of electronic characteristics including charge distribution, energy levels, spin-orbit coupling (SOC), and charge transport properties. Nevertheless, in-depth and comprehensive reviews on the progress of RVDA are still lacking. Therefore, this Account aims to summarize our research on the molecular design and properties of RVDA materials, along with recent advances across diverse application fields. It begins by introducing the fundamental principles of RVDA in dynamically modulating optoelectronic properties, following by the four systems based on their molecular structure design considerations. We highlight the diverse types of RVDA materials while discussing recent developments, including the latest research on host materials for organic light-emitting diodes (OLEDs), organic ultralong room-temperature phosphorescence (OURTP) materials for data encryption, fluorescence emitters for sensors, and hole transport materials (HTMs) for perovskite solar cells (PSCs). A key objective of this Account is to extract the fundamental design principles of RVDA materials and to uncover the common relationships between molecular structures and their optoelectronic properties across different research areas, systematizing our understanding of this field. Finally, current challenges are analyzed to outline future research directions, aiming to provide insights and guidance for developing next-generation smart materials and thereby expanding their transformative applications in organoelectronics, flexible electronics, bioelectronics, and related fields.
Chen et al. (Mon,) studied this question.