有機半導體分子之合成、薄膜形貌與場效電晶體性質研究

Synthesis, Film Morphology and Field-Effect Transistor Property of Organic Semiconductor Molecules

魏菱均(Ling-Chun Wei)

指導教授 ： 陶雨台

國立清華大學/理學院/化學系/碩士(2006年)

摘要

本研究主要以寡聚噻吩的衍生物DHB-4T, DFB-4T 及五環素的衍
生物DP-PT, DTh-PT, DTo-PT 做為有機半導體分子。在不同的基板
溫度下，以真空蒸鍍的方式將化合物沉積於二氧化矽表面以及用飽和
十八烷基三氯矽烷(OTS)、雙(三甲基矽)胺(HMDS)及苯甲基三氯矽烷
(BTS)等自組裝單層膜分子修飾過的二氧化矽表面上，研究薄膜結構
與場效電晶體性質關係。
藉由原子力顯微鏡影像及X-ray 繞射圖譜結果觀察分子在表面的
形貌：對DHB-4T 而言，是以接近站立的方式在表面堆疊，且晶體大
小隨著基板溫度的上升而變大；而五環素的衍生物幾乎為非晶相的堆
疊。場效特性則是在有機膜的上方沉積上金作為汲極與源極後，以半
導體參數分析儀量測。DHB-4T 為一正型的半導體材料，所得到的最
大場效載子遷移率隨著溫度變化可從0.028 上升到0.17 cm2V-1s-1；而
以五環素的衍生物為半導體層的電晶體所得到的最大場效載子遷移
率約10-3 cm2V-1s-1。
另一方面，將自組裝單層膜經過刷磨後，沉積上DHB-4T，所使
用的自組裝單層膜為十八烷基三氯矽烷(OTS/SiO2/Si)以及九烷基三
氯矽烷(NTS/SiO2/Si)。希望藉此觀察刷磨自組裝單層膜對於晶體顆粒
大小與場效載子遷移率(field-effect mobility)的影響。

關鍵字

場效電晶體 ； 有機半導體

並列摘要

Oligothiophene derivatives DHB-4T, DFB-4T and pentacene derivatives DP-PT, DTh-PT, DTo-PT were synthesized and characterized as the active channel material in the organic FET. Structure of thin-film as a function of substrate surfaces ( bare silicon dioxide (SiO2/Si) substrate, n-octadecyltrichlorosilane (OTS/SiO2/Si)-, benzyltrichlorosilane (BTS/SiO2/Si)-, and 1,1,1,3,3,3-hexamethyldisilazane (HMDS/SiO2/Si)-treated surfaces) and temperature were examined.
For DHB-4T, a near perpendicular molecular orientation was observed in most cases, with grain size increasing with increasing substrate temperature. Field effect mobilities were measured employing a top source-drain contact configuration. DHB-4T exhibited p-type semiconducting behavior with maximum field-effect mobility ranging from ~0.028 to ~0.17 cm2V-1s-1, depending on the substrate temperature. DP-PT and DTh-PT also exhibited p-type behavior with maximum field-effect mobilities ~ 10-3 cm2V-1s-1.
Additionally, DHB-4T was also deposited on a rubbed SAM of n-nonyltrichlorosilane (NTS/SiO2/Si) and n-octadecyltricholrosilane (OTS/SiO2/Si) surfaces to examine the effect of rubbing on the crystal size and charge mobility.

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