Characteristics and Durability of Vertical-Type Organic Light-Emitting Transistors Using Poly(2-methoxy-5-(2- ethyl hexyloxy)-1,4-phenylenevinylene) and Indenofluorenedione Derivatives.

In this study, we have fabricated vertical organic light emitting transistors using indenofluorenedione derivatives (IF-dione-F) as an n-type organic semiconductor. IF-dione-F shows high performance n-type semiconductors owing to the fluorine group in the IF-dione-F backbone. The fluorine group has an electron-withdrawing property. Thus, IF-dione-F shows high electron affinity and good durability. The configuration of the vertical organic light emitting transistors was ITO (drain)/ PEDOT: PSS/MEH-PPV/IF-dione-F/AI (gate)/IF-dione-F/Al (source). The characteristics of the vertical organic light emitting transistors were investigated from the measurements of radiancevoltage characteristics and external quantum efficiency. Furthermore, air stability was studied from the measurements of characteristics, impedance spectroscopy and contact angle.

Studies on the Characteristics of Vertical Organic Transistor with Nano Patterned Gate Using Block Copolymer.

In this study, we fabricated and studied the device characteristics of vertical organic transistors consisting of nano-patterned gates constructed from the self-assembly of block copolymer. The size of the gate opening made by the new method was 30~40 nm. The device was compared with those which had gate openings of 200 nm. These lager devices were constructed from monodispersed colloidal polystyrene spheres. The device which used block copolymer showed significant improvements in its on-off ratio. We also fabricated transistors with tungsten oxide buffer layer to increase the on current of the device. The devices were analyzed based on their current-voltage charac- teristics, impedance spectroscopy, atomic force microscope (AFM) images and scanning electron microscope (SEM) images.