具醯亞胺鍵結之環氧樹脂高分子做為光電材料的特性探討與鑑定

Abstract

在本研究中，合成含有醯亞胺鍵結之環氧樹脂交聯高分子DIDE-TAPA以及DIDE-DO3-TAPA應用在有機場效薄膜電晶體 (OTFTs) 之高分子層。使用N型半導體NDI-C7F9作為半導體層材料，由於以N行半導體中的NDI衍生物在大氣中擁有良好的穩定性，因此所做成的N型通道之OTFTs元件，可在大氣下製備並量測。此外，還使用P行半導體Pentacene作為半導體材料以做比較。本研究中所合成的含有醯亞胺鍵結之環氧樹脂交聯高分子應用於兩元件之平均載子遷移率(Mobility)約為10-2~10-3 cm2V-1s-1，開關電流比為102~103。而因使用了具有儲存電荷能力的三苯胺結構做為交聯劑，可使得所做出的元件具有記憶效應，以DIDE-TAPA作為高分子層且半導體材料為NDI-C7F9時，其Memory Window 為60V，而另外添加具有D-A結構以增加記憶體效應之DO3的對照組也表現Memory Window 為70V。此外，研究中利用原子力顯微鏡以及掃描式電子顯微鏡偵測半導體層的表面形貌，並以X光繞射觀察半導體小分子在不同介電層改質之基板上的排列及堆積密度，此外接觸角、介電常數、熱性質等分析也在此研究中被進行探討。

This work presents synthesis and characterization of different imide-epoxy polymers, namely DIDE-TAPA and DIDE-DO3 to be used as polymeric layer in organic thin film transistors. NDI-C7F9, a tetracarboxylic diimide derivative, was used as n-type semiconducting layer of OTFT due to its good stability in air. In addition, pentacene, a widely used p-type semiconductor, was also used as a semiconducting layer. Organic thin film transistors were fabricated by spinning the imide-epoxy polymers as dielectric layer/polymeric layer on Si/SiO2 substrates, and then depositing the semiconducting layers in vacuum. The electron mobility and on/off ratio of all devices measured in the air were about 10-2~10-3 cm2V-1s-1 and 102~103, respectively. Using triaminophenylamine (TAPA) as a crosslinker could result in memory effect. The device, using NDI-C7F9 as semiconductor layer and DIDE-TAPA as polymeric layer, exhibited a memory window of approximately 60V. Moreover, the introduction of polymers with D-A structure as the polymeric layer could possibly enhance the memory effect of the OTFT devices. The devices using NDI-C7F9 as semiconductor layer and DIDE-DO3-TAPA as polymeric layer exhibited a memory window of approximately 70V. Furthermore, better film quality would favor the ordered arrangement of semiconductors. Hence the contact angle, dielectric constant and thermal stabilities of dielectric layer such as were also studied in this work. Moreover, the investigation of the morphological influence on semiconducting layers was performed by atomic force microscopy (AFM) scanning electron microscope (SEM) and X-ray diffraction (XRD)