Molecular Photoinduced Charge Separation: Fundamentals and Application

Abstract

Abstract We have designed and synthesized a number of donor-acceptor linked systems to elucidate the science of photoinduced charge separation. In particular, porphyrin-fullerene and polymer-fullerene linked molecules have been found to be very useful as model systems for addressing issues in excited-state generation, charge separation, and charge dissociation. We have also proposed a new concept, “dynamic exciton” to establish new comprehensive photochemistry dealing with manipulation of locally excited state, charge-transfer state, and charge-separated state involving mutual transformation. Simultaneously, it is pivotal to adopt time-dependent dynamic effects on electron and spin behaviors entangled with movement of atomic nuclei (i.e., vibration, rotation, and fluctuation) and their collective motion into molecular donor-acceptor systems. Versatile dyes for dye-sensitized solar cells as well as donor/acceptor molecules for bulk heterojunction organic solar cells have also been tailored toward better understanding the underlying mechanism as well as improving their photovoltaic performances. Meanwhile, giant dipole moment produced from donor-acceptor linked molecules by light has been successfully utilized to regulate the membrane potential of living biological cells. This is the first example of the use of charge-separated state in optogenetics and is promising as neuronal therapy by light.