新型 HBC 分子應用於石墨烯之剝離與修飾及表面自組裝

Abstract

於本研究第一部分，我們合成了新型的六苯并蔻（hexa-peri-hexabenzocoronene, HBC）衍生物，以應用於石墨烯液相剝離法（liquid-phase exfoliation of graphite）。在HBC衍生物的作用下，我們成功地製備出單層以及多層石墨烯產物。我們亦針對該石墨烯的物理及化學性質進行了詳細的分析。石墨烯溶液可利用陽極氧化鋁模版（anodic aluminum oxide）過濾及收集，並轉置於玻璃基版上，形成半透明的導電薄膜。 在我們合成的六苯并蔻衍生物中，其中一種具有兩親性質（amphiphilic）的分子HBC-6ImBr有著修飾石墨烯表面性質的潛力。我們將它塗布在以化學氣相沈積法製備的石墨烯電極上，成功將其疏水性表面改質為親水性表面，藉以改善石墨烯電極與傳統有機電洞傳輸材料的作用力。在有機發光二極體（OLED）的應用中，我們成功地利用此方法提昇了元件的發光效率。 於本研究第二部分，我們將兩種具有速配化學（click chemistry）官能基的六苯并蔻衍生物於矽基版的表面製備成自組裝單層膜（self-assemble monolayer）。藉由調控六苯并蔻的化學結構，便可控制自組裝單層膜的排列方向。其後，六苯并蔻於表面的堆疊方式將會受到自組裝單層膜的引導，令分子形成平躺（face-on）或是側立（edge-on）的薄膜。我們運用此技術來製備有機薄膜場效電晶體，並成功觀察到分子排列對於元件表現的影響。

In the first topic, we reported the synthesis and characterizations of new peripheral-functionalized hexa-peri-hexabenzocoronene (HBC) derivatives, which were utilized for the sonication-assisted liquid-phase exfoliation (LPE) of graphite to give graphenes sandwiched by HBCs in one single step. The graphene products were collected and transferred onto glass, giving the semi-transparent conductive film. One of the amphiphilic HBC derivatives, HBC-6ImBr, has the potential to modify the CVD-graphene electrode, rendering it the hydrophilic surface. The molecule is fabricated as the interlayer between the graphene electrode and the hole-transporting layer in OLEDs. The performance is distinctly enhanced by the non-destructive surface modification. In the second topic, planar hexa-peri-hexabenzocoronene was immobilized on the silicon wafer via click-chemistry, giving the self-assemble monolayer (SAM) on the surface. The face-on and edge-on morphology of SAM could be manipulated by tailoring the chemical structure of HBC. Controlled by the morphology of SAM, the following HBC molecules could stack on the surface with specific orientations. The anisotropic character was further applied in the thin-film transistor (TFT) fabrication.