Increasing charge carriers of channel in organic field-effect transistor by corona poling process to PVDF-based dielectric layer
발표자
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초록
내용
In OFETs, organic dielectric materials have been used for the dielectric layer, but their dielectric constants are lower than those of inorganic dielectric materials. To overcome this issue, we demonstrated large enhancement of the capacitance of PVDF-based high-k dielectric, Poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (k~ ＞50), by applying the corona poling process. The poling process can align the dipoles of high-k dielectric polymer, and low-k dielectric layer was deposited between the active and high-k dielectric layers to reduce the trap sites. This process improved the hole mobility from 0.359 cm2/Vs to 0.520 cm2/Vs and decreased the threshold voltages in DPPT-TT based OFET. These improvements derived from corona poling are ascribed to enhanced capacitance of dielectric from 37.59 nF/cm2 to 42.87 nF/cm2 inducing more charge carriers. These results suggest an effective way to improve the electrical characteristics of OFETs by controlling polymer alignment.