Regulation of molecular orientation in organic solar cells

The morphological characteristics of the active layer in organic solar cells (OSCs), encompassing phase separation structure, domain sizes, crystallinity and molecular orientation play a pivotal role in governing the photoelectric conversion processes. Notably, molecular orientation holds paramount significance as it exerts influence over key aspects such as light absorption, exciton dissociation, charge transport, and collection. Thus, a comprehensive comprehension of the impact of molecular orientation on the photophysical processes and strategies for regulating molecular orientation is imperative. This discussion delves into the influence of molecular orientation on the power conversion process, encompassing aspects such as donor and acceptor energy alignment, the efficiency of exciton dissociation, and charge transport. Additionally, a thorough analysis of the control of molecular orientation, incorporating molecular design and physical means, is undertaken, elucidating the underlying principles. Finally, the discourse concludes with an exploration of challenges and prospects associated with the advancement of OSCs.