Organic semiconductors, Organic field-effect transistors, Semiconductor device physics, Metal/semiconductor interface, Charge transport, Self assembly

Organic semiconductor device physics

The electrical performance of organic field-effect transistors (OFETs) is limited by the low mobility as well as the large contact resistance. He has investigated the fundamental mechanisms of charge injection and transport processes in OFETs to reveal the origins of the low mobility and large contact resistance for practically applicable organic electronic products.

Self assembly of organic semiconductors

Depending on the structural configuration, functional groups, and electron state, organic molecules can self assemble and exhibit distinctive optical and electronic properties. He has developed solution-based self assembly of organic semiconductors where molecules can self organize and crystallize at desired locations on the substrate. This method can be effectively used for fabrication of organic electronics devices.

Solution-processed organic field-effect transistors by high-resolution printing

The solubility and low processing temperatures of organic semiconductors enable fabrication of electronic devices using simple printing technologies. In particular, if all the layers of an OFET can be deposited and patterned by printing techniques under ambient atmosphere, the production cost of semiconductor devices can be substantially reduced. In this sense He has developed an all-solution fabrication process for OFET devices, in which all the layers of OFET devices (gate electrode, gate insulator, source/drain electrode, organic semiconductor layer) are patterned by solution-based patterning techniques. These printed devices showed high OFET performance.