Excited-State Molecular Engineering for Multifunctional Organic Electronics: From Color-Cognitive Memristors to Efficient Hole Transport in Perovskite Solar Cells

Organic semiconductors exhibiting controllable excited-state properties offer unique opportunities for the development of next-generation multifunctional electronic devices. In this presentation, we highlight two representative applications that exploit light-induced molecular responses to achieve advanced optoelectronic functionalities.

First, we introduce a color-cognitive memristor based on photoresponsive organic semiconductors with light-enhanced molecular polarity. The wavelength-dependent modulation of charge transport enables multispectral conductance switching and visual information recognition, mimicking key aspects of biological vision systems. Such behavior provides a promising platform for neuromorphic visual computing and artificial sensory memory.

Second, we demonstrate that excited-state proton-transfer characteristics and aggregation behavior can be strategically utilized to improve hole-transport performance in heterocyclic organic semiconductors. By incorporating these materials into NiOx-based hybrid hole-transport layers for perovskite solar cells, enhanced charge extraction, suppressed interfacial recombination, and improved photovoltaic performance are achieved. The synergistic relationship between molecular excited-state processes and charge-transport characteristics provides valuable design principles for high-performance energy devices.

These studies collectively illustrate how excited-state molecular engineering can bridge sensing, information processing, and energy conversion, offering a versatile framework for the future development of multifunctional organic electronic systems.