Organic field-effect transistors(OFETs) are attracting more and more attention due to their potential applications in low-cost, large-area and flexible electronic products. Organic semiconductors(OSCs) are the key components of OFETs and basically determine the device performance. The past five years have witnessed great progress of OSCs. OSCs used for OFETs have made rapid progress, with field-effect mobility much larger than that of amorphous silicon(0.5?1.0 cm2/(V s)) and of up to 10 cm2/(V s) or even higher. In this review, we demonstrate the latest progress of OSCs for OFETs, where more than 50 representative OSCs are highlighted and analyzed to give some valuable insights for this important but challenging field.
We have fabricated hybrid molecular chain structures formed by electron acceptor compound 1 and electron donor molecules 2 and 3 at the liquid/solid interface of graphite surface.The structural details of the mono-component and the binary assemblies are revealed by high resolution scanning tunneling microscopy (STM).Compound 1 can form two well-ordered lamellar patterns at different concentrations.In the co-adsorption structures,compounds 2 and 3 can insert into the space between molecular chains of compound 1 and form large area well-ordered nanoscale phase separated lamellar structures.The unit cell parameters for the coassemblies can be "flexibly" adjusted to make the electron donors and acceptors perfectly match along the molecular chains.Scanning tunneling spectroscopy (STS) results indicate that the electronic properties of individual molecular donors and acceptors are preserved in the binary self-assembly.These results provide molecular insight into the nanoscale phase separation of organic electron acceptors and donors on surfaces and are helpful for the fabrication of surface supramolecular structures and molecular devices.
The organic single-crystal field-effect transistors using anthracene derivative, H-Ant as an active layer with source/drain electrodes decorated by metal charge transfer salt(Cu TCNQ) were fabricated. We demonstrated that this bottom-contact structure displayed an obvious improvement in the electrical characteristics relative to their pristine copper and top-contact gold electrode counterparts. This observation could be ascribed to the lower contact resistance resulting from the energetic match between electrodes and semiconductor.
Liangfu HeDeyang JiErjing WangYonggang ZhenHuanli DongWenping Hu
