運用奈米壓印技術製作之空間電荷限制電晶體與四併環□吩高分子材料電晶體

Abstract

由於可製備於可饒式基板上的特性是為電子元件製程上降低成本以及大面積化之關鍵，故相關於溶液製程的有機電晶體研究日漸增加。在本研究中，我們成功地利用奈米壓印技術製備具規則排列孔洞金屬基極的空間電荷限制電晶體。在過去的研究中，為利用自組裝非緊密排列之聚苯乙烯（PS）球作為金屬基極蒸鍍遮罩的製程製作具隨機排列孔洞之金屬基極，然而聚苯乙烯（PS）球的隨機排列將容易出現因球聚集而造成孔洞過大的問題，過大的孔洞將使基極對孔洞中心區域的控制能力降低，並進而導致垂直通道結構電晶體的漏電流。在本研究中，已成功利奈米壓印技術製備出具規則排列孔洞的金屬基極，並使元件具有開電流0.35 mA/cm2以及開關電流比3000之元件特性，並相信經過適當的製程改良後，更佳的元件特性將可被預期。 在本研究的第二部分中，我們將使用相對於P3HT更具有空氣穩定性的四併環□吩高分子材料 P2TDC13FT4作為主動層材料，探討其在垂直通道結構電晶體上的特性，在文獻中，P2TDC13FT4應用於水平通道結構有機薄膜電晶體OTFT時，經過適當的自組裝分子層(SAM)處理後，其載子遷移率可達0.3 cm2/V•s，並在特定環境下元件經過九個月不會有明顯的特性衰退。在本實驗中，我們製備以P2TDC13FT4作為主動層材料之空間電荷限制電晶體，並在大氣環境下觀察到，相較於以P3HT為主動層材料之元件，以P2TDC13FT4 作為主動層材料之元件具有更佳的空氣穩定性，此一結果將有助於空間電荷限制電晶體在未來之應用與發展。

Research on solution-processed organic transistors is increasing because organic transistors can be fabricated on flexible substrates serving as key components of low-cost and large-area electronic devices. In this work, we fabricate the well-ordered porous base metal structure of space-charge-limited transistor (SCLTs) by nano-imprint technology. We obtain an on current as 0.35mA/cm2 and an on/off current ratio around 3000 at VCE as 1.8 V. The performance is better than our first reported SCLT in 2006 when randomly distributed polystyrene spheres were used as the hard mask. This research, the imprinted SCLT, is the first successful demonstration of the feasibility to use nano-imprint technology to fabricate SCLT. The result provides a reliable way to mass produce the metallic nano-grid in large area. In the future, with further process optimization, a better device performance can be expected. In the second part of this research, the study of poly(2,5-bis(thiophene-2-yl)-(3,7-ditri-decanyltetrathienoacene), P2TDC13FT4, is discussed through the space-charge-limited transistors. Air-stable P2TDC13FT4 with a high highest occupied molecular orbital energy level was utilized as the polymer nanorod material for the first time in a space-charge-limited transistor. We fabricated P2TDC134FT4-based SCLTs through the deposition of P2TDC13FT4 in low melting point solvent and the treatment of SAM. In atmospheric environment, compared to the devices which utilized P3HT as the active layer material, the P2TDC13FT4-based SCLT demonstrated better air stability. This result will contribute to the applications and development of SCLT in the future.