화학공학소재연구정보센터
학회 한국고분자학회
학술대회 2005년 가을 (10/13 ~ 10/14, 제주 ICC)
권호 30권 2호
발표분야 분자전자 부문위원회
제목 Anisotropic character of charge carrier mobility through the alignment techniques in thin-film transistors
초록 Organic thin film transistors (OTFTs) have received enormous interests as a low-cost and flexible alternative to amorphous silicon transistors for electronic applications of large-area circuits. OTFT device performance such as high charge carrier mobility, Ion/Ioff ratio and low leakage current are required. The charge carrier mobilities have been known as highly dependent on the orientation of molecule and grain size of crystal in OTFTs. A uniaxial alignment of semiconductor materials along the channel direction is a good method not only to reduce leakage currents within other channels but also to increase charge carrier mobility. The rubbing method has been widely used in actual production of liquid crystal displays (LCDs) for aligning liquid crystals (LCs). We have applied that concept to OTFTs. Since polyimides are used in LCDs as the material to align LCs, polyimide(SE-7492) has been spin-coated as the alignment layer on silicon wafer. Pentacene is a rigid rod-like molecule similar to the core structure of a liquid crystal. In consequence, we have deposited pentacene as a semiconductor layer on it. The LC molecules are more likely to be aligned by interactions with the polymer main chains and their side groups rather than by the micro grooves. Similarly to that, these relations between the two effects in OTFT have been studied through the comparisons of other rubbed buffer layers. The rubbed polyimide will be characterized through in-plain birefringence by ellipsometry. And the in-plain structure of pentacene will be presented through X-ray diffraction. Finally the anisotropic mobilities of pentacene layer will be measured through field-effect method.
저자 강석주1, 노용영2, 김지은3, 백강준1, 김동유1
소속 1광주과학기술원, 2OE Group, 3Cavendish Laboratory Univ. of Cambridge
키워드 OTFT; pentacene; rubbing technique
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