刮刀製程搭配高載子遷移率之高分子於垂直式空間電荷限制電晶體

Abstract

相較於小分子有機半導體的製程高成本及製程複雜，可液態製程、可製做在軟性可繞基板等優勢使共軛高分子在有機半導體領域近年來受到相當的注目。現今多數採液態製程的高分子有機半導體是採以旋轉塗佈法來成膜，但其材料使用率不高。本文引入刮刀塗佈技術成膜，此技術已被證實可做為提升材料使用率的的方法。Poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14)是一種液晶分子，藉由高溫退火進入液晶相及快速冷卻維持退火後的晶相，可使得其載子遷移率提升，而PBTTT二極體的電流密度表現也比poly(3-hexylthiophene-2, 5-diyl) (P3HT)來的高。最後，我們嘗試對poly(9,9-di-noctylfluorene-alt-(1,4-phenylene -((4- sec -butylphenly)-imino-)- 1,4-phenylene) (TFB)進行tetrafluoro -tetracyanoquinodimethane (F4TCNQ) 摻雜，在不同濃度的摻雜下，尋求最佳的摻雜濃度。

Comparing to high cost and complicated fabrication process of small molecule organic semiconductor devices, conjugated polymer have been widely explored because of its advantages such as soluble process and its flexibility. Although spin coating is the most common technique for casting polymer films in solution process, its material usage is low. In this work, we use the blade coating method which has been demonstrated to have a high material usage. We demonstrate that even the solubility of a polymer is low, by using the blade coating method, the polymer film can still be fabricated easily. Poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14) is a kind of liquid crystal molecule. By annealing at high temperature and transient cooling, its liquid crystal phase and high carrier mobility can be obtained. PBTTT diode shows higher current density compared to poly(3-hexylthiophene -2,5-diyl) (P3HT) diode. Finally, we demonstrated the influence of different concentration tetrafluoro -tetracyanoquinodimethane (F4TCNQ) doping on the poly(9,9-di-noctylfluorene-alt -(1,4-phenylene-((4-sec-butylphenly)-imino-) -1,4-phenylene) (TFB) diode.