  Organic phototransistors (OPTs), compared to traditional inorganic
counterparts, have attracted a great deal of interest because of their inherent
flexibility, light-weight, easy and low-cost fabrication, and are considered as
potential candidates for next-generation wearable electronics. Currently,
significant advances have been made in OPTs with the development of new organic
semiconductors and optimization of device fabrication protocols. Among various
types of OPTs, small molecule organic single crystal phototransistors (OSCPTs)
standout because of their exciting features, such as long exciton diffusion
length and high charge carrier mobility relative to organic thinfilm
phototransistors. In this review, a brief introduction to device architectures,
working mechanisms and figure of merits for OPTs is presented. We then overview
recent approaches employed and achievements made for the development of OSCPTs.
Finally, we spotlight potential future directions to tackle the existing
challenges in this field and accelerate the advancement of OSCPTs towards
practical applications.
