Abstract
Emerging monolayer molecular crystals (MMCs) have become prosperous in recent decades due to their numerous advantages. First, downsizing the active layer thickness to monolayer in organic field-effect transistors (OFETs) is beneficial to elucidate the intrinsic charge-transport behavior. Next, the ultrathin conducting channel can reduce bulk injection resistance to extract mobility accurately. Then, direct exposure of the conducting channel can enhance the sensing performance. Finally, MMCs combine the merits of ultrathin thickness and high crystallization, which will improve the optoelectronic performance and realize complex device architectures for future advanced optoelectronic applications. In this Review, recent research progress in precise preparations and advanced applications of solution-processed MMCs are summarized. We present the current challenges related to MMCs with specific structures and desired performances, and an outlook regarding their application in next-generation integrated organic optoelectronics is provided.