화학공학소재연구정보센터
Advanced Functional Materials, Vol.19, No.5, 789-795, 2009
Monitoring the Channel Formation in Organic Field-Effect Transistors via Photoinduced Charge Transfer
Conducting channel formation in organic field-effect transistors (OFETs) is considered to happen in the organic semiconductor layer very close to the interface with the gate dielectric. In the gradual channel approximation, the local density of accumulated charge carriers varies as a result of applied gate bias, with the majority of the charge carriers being localized in the first few semiconductor monolayers dose to the dielectric interface. In this report, a new concept is employed which enables the accumulation of charge carriers in the channel by photoinduced charge transfer. An OFET employing C-60 as a semiconductor and divinyltatramethyldisiloxane-bis(benzocyclobutene) as the gate dielectric is modified by a very thin noncontinuous layer of zinc-phthalocyanine (ZnPc) at the semiconductor/dielectric interface. With this device geometry, it is possible to excite the phthalocyanine selectively and photogenerate charges directly at the serniconductor/dielectric interface via photoinduced electron transfer from ZnPc onto C-60. Thus the formation of a gate induced and a photoinduced channel in the same device can be correlated.