Control of Threshold Voltage for Top-Gated Ambipolar Field-Effect Transistor by Gate Buffer Layer.
The threshold voltage and onset voltage for p-channel and n-channel regimes of solution-processed ambipolar organic transistors with top-gate/bottom-contact (TG/BC) geometry were effectively tuned by gate buffer layers in between the gate electrode and the dielectric. The work function of a pristine Al gate electrode (-4.1 eV) was modified by cesium carbonate and vanadium oxide to -2.1 and -5.1 eV, respectively, which could control the flat-band voltage, leading to a remarkable shift of transfer curves in both negative and positive gate voltage directions without any side effects. One important feature is that the mobility of transistors is not very sensitive to the gate buffer layer. This method is simple but useful for electronic devices where the threshold voltage should be precisely controlled, such as ambipolar circuits, memory devices, and light-emitting device applications.
Department of Energy and Materials Engineering, Dongguk University , 30, Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea.|Center for Plastic Electronics, Department of Physics, Blackett Laboratory, Imperial College London , London SW7 2AZ, United Kingdom.
Dongyoon
D
Khim
Department of Energy and Materials Engineering, Dongguk University , 30, Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea.
Eul-Yong
EY
Shin
Department of Energy and Materials Engineering, Dongguk University , 30, Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea.
Yong
Y
Xu
Department of Energy and Materials Engineering, Dongguk University , 30, Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea.
Won-Tae
WT
Park
Department of Chemistry Education, Graduate Department of Chemical Materials, and Institute for Plastic Information and Energy Materials, Pusan National University , Busan 609-735, Republic of Korea.
Sung-Ho
SH
Jin
Department of Energy and Materials Engineering, Dongguk University , 30, Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea.
Yong-Young
YY
Noh
ambipolar transport; buffer layers; flat-band voltages; organic-field effect transistors; threshold voltages