Chiroptical Neuromorphic Phototransistor Based on Self-Assembled Supramolecular Nanostructure of Diketopyrrolopyrrole-Based π-Conjugated Organogelator

Chiral optoelectronic has gathered significant attention in various applications of quantum computation, optical spintronics, bio-sensing, 3D imaging, and encryption. To realize chiral optoelectronics technology, the development of chiroptical optoelectronic devices, which can provide distinguishable electrical signals according to the handedness of circularly polarized (CP) light (i.e., right- or left-circular polarization) is essential. From a viewpoint of materials, chiral π-conjugated molecules of whose chiroptical properties can be effectively controlled by programmable molecular design are one of the key materials to impart the chiroptical activity of the optoelectronic device. So far, many demonstrations of chiroptical π-conjugated molecules and their supramolecular structures have been intensively demonstrated, however, the development of chiroptical optoelectronic devices based on chiral pi-conjugated molecules or their supramolecular structure is rarely reported.<br/>In this work, we propose a chiroptical hybrid phototransistor based on the supramolecular nanohelix of a π-conjugated molecule for neuromorphic imaging technology. To provide highly strong chiroptical activity to the transistor, diketopyrrolopyrrole-based donor-acceptor type orgaogelator (DPP-organogelator) was newly synthesized. Supramolecular nanohelix structure of DPP-organogelator was successfully fabricated under optimized self-assembly conditions and exhibited strong and stable chiroptical properties. The suggested chiroptical hybrid phototransistor based on the DPP-organogelator nanohelix distinguishably detected the circularly polarized light with the different circular polarization directions. Especially, the device exhibited the frequency-dependent plasticity behavior in the photocurrent. Based on this, we successfully developed unique chiroptical imaging sensors showing enhanced contrast in the images obtained under cp light with different polarization directions.