本論文應用膠體微影技術於垂直有機電晶體中的開孔式源極，並研究垂直電晶體電流特性。對於垂直電晶體的開/關能力而言，源極的奈米孔洞結構與源極功函數/有機半導體的蕭特基能障為重要兩關鍵。利用膠體微影技術可獲得大面積(cm2)、高均勻性的單層奈米球膜，且製作出高密度和高均勻性的孔洞覆蓋率開孔源極。此外選擇高功函數之金和銀作為源極金屬，以及N型小分子有機半導體碳六十(C60)作為垂直電晶體之主動層，研究開孔源極的孔洞覆蓋率、金屬功函數對於垂直電晶體電性表現之影響。實驗結果發現，30 %孔洞覆蓋率可觀察到明顯的開/關表現，及藉由以全氟癸烷硫醇(PFDT)自組性單分子層修飾銀源極功函數來有效提升銀源極與C60間的蕭特基能障，相較於未經修飾的銀源極，可進一步壓抑關電流密度高達三個數量級。整體而言，經由優化銀源極的孔洞覆蓋率與功函數並鍍製適當厚度的C60主動層，其垂直電晶體的開/關比接近104和開電流密度可達1~10 mA/cm2，此電性表現在未來可進一步與OLED整合並應用於顯示器中。;This thesis investigates the application of colloidal lithography technique on patterned source electrode of vertical organic transistor and characterizes the devices electrical properties. For the on/off ability of vertical transistor, nanopatterned structure of source electrode and the Schottky barrier of source electrode/organics interface are two important factors. Large area (cm2) and high uniformity of nanosphere monolayer is obtained by utilizing the colloidal lithography method. Also, the high density and uniform hole surface coverage patterned electrode is demonstrated. The vertical transistor fabricated with high work function source electrode (Ag and Au) and N-type C60 small molecules semiconductor. We correlate the vertical transistor electrical performance with the hole surface coverage and the work function of patterned source electrode. From results of experiments, the transistor on/off performance with 30% hole surface coverage of source electrode is clearly observable. And, the Ag/C60 Schottky barrier is effectively increased by modifying Ag source electrode work function with PFDT self-assembled monolayer, which shows that the off current density of Ag/PFDT-source transistor can be a factor of 103 lower than Ag-source transistor. In summary, with optimized hole surface coverage, modified Ag source electrode work function, and sufficiently thick C60 active layer, the vertical transistor with on/off ratio of nearly 104 and the on current density of 1-10 mA/cm2 are demonstrated, which is promising for applications of OLED display technology in the future.
