以無磁滯現象可光圖型化介電層製作之可撓式有機薄膜電晶體

Abstract

在有機薄膜電晶體中，介電層是重要的結構之ㄧ，本實驗以旋轉塗佈、微影蝕刻、利用高分子光反應交聯(photo cross-link)的方式製造可光圖型化(photopatternable)之高分子介電層。我們使用摻雜三氧化鉻(CrO3)之PVA以及PVCN兩種可光圖型化高分子介電材料，並以熱蒸鍍五環素(pentacene)和金分別作為主動層和電極材料。由實驗結果可知，PVA介電層元件有相當大的磁滯現象，推測主要可能來自PVA本身的氫氧根(OH groups)，而PVCN介電層元件不論在玻璃或不□鋼軟性基板上皆無磁滯現象，也具有較佳開關比以及在空氣中穩定性等優點。此外在不鏽鋼軟性基板上， PVCN介電層元件在彎曲量測上幾乎沒有任何衰減。

Polymer gate dielectrics are the most promising dielectric candidates for organic thin-film transistors (OTFT). In this study, we used photo cross-linked polymers as the photopatternable polymer dielectric layer. Two kinds of photopatternable polymer insulators, polyvinyl alcohol (PVA) and polyvinyl cinnamate (PVCN). Thermally evaporated pentacene and gold were used as the active layer and the source-drain electrodes.The result showed that PVA-based devices have large hysteresis, which was probably due to the OH groups of PVA. On the other hand, PCVN-based devices exhibited hysteresis-free performance. Moreover, the PCVN-based devices also have higher on/off ratios and the devices were more air-stable. For the bending measurements, we observed no significant decay of the field-effect for the devices made on flexible stainless substrates.