以刮刀塗佈法製作TIPS-pentacene有機薄膜電晶體元件之特性探討

Characteristics of TIPS-pentacene based organic thin film transistors fabricated by blade coating method

蔡岳霖(Yueh-Lin Tsai)

指導教授 ： 黃振昌

國立清華大學/工學院/材料科學工程學系/碩士(2014年)

摘要

本論文以水溶性的明膠蛋白作為閘極介電層，可溶性的P型半導體小分子6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) 作為主動層，利用溶液製程製作可撓曲之有機薄膜電晶體。其中，TIPS-pentacene主動層薄膜是以刮刀塗佈 (blade coating) 的方式製作，由實驗結果可知，其塗佈參數會大幅影響元件特性。當基板溫度為70 ℃，並以1 mm/sec的塗佈速率沿平行元件載子傳遞通道的方向進行塗佈時，可得最佳元件特性，其載子遷移率可達1.71 cm2V-1s-1。
以AFM及XRD對TIPS-pentacene薄膜進行分析可發現，當基板溫度為70 ℃ ，以1 mm/sec進行塗佈時，能使TIPS-pentacene晶體沿塗佈方向成長，其薄膜表面會形成長板狀的長程有序結構，大幅改善結晶性，能獲得最佳之元件特性。
實驗也印證了當TIPS-pentacene晶體有方向性的成長時，其電晶體元件在電性上具有非等向性。塗佈方向的不同會明顯的影響載子遷移率，因此凸顯了晶體成長方向對電性好壞的重要性。

關鍵字

有機薄膜電晶體 ； 明膠蛋白 ； 刮刀塗佈 ； TIPS-pentacene

並列摘要

In this thesis, we fabricated flexible OTFT devices with soluble gelatin as gate dielectric and soluble p-type TIPS-pentacene as the semiconductor layer by using solution process. We found that the parameters of blade coating would affect the characteristics of OTFT devices significantly. The best characteristics of OTFT device occur when the TIPS-pentacene thin film is coated along the charge transport channel with a coating speed of 1 mm/sec at a substrate temperature of 70 ℃. Its field effect mobility is up to 1.71 cm2V-1s-1.
Based on AFM and XRD, the crystal of TIPS-pentacene grows along the coating direction when the coating speed is 1 mm/sec and the substrate temperature is 70 ℃. The thin film morphology consisted of many plate-like domains with long-range ordering and the crystallinity increases a lot at the same coating speed and substrate temperature. The formation of plate-like domains and the increment of crystallinity are responsible for better OTFT devices characteristics.
We have also demonstrated that the anisotropy of the electrical characteristics of the OTFT devices is in match with oriented TIPS-pentacene crystal growth direction. The influence of coating direction on field effect mobilities is also illustrated.

並列關鍵字

OTFT ； gelatin ； blade coating

參考文獻

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