紫外光保護層於有機薄膜電晶體之研究

Abstract

在這份論文中, 我們製造N, N' bis(naphthalen 1 y) N, N'-bis(phenyl) 二氨基聯苯(NPB)保護層保護有機薄膜電晶體(OTFTs)在紫外光照射之下免受退化。有熱蒸鍍沉積的二氨基聯苯(NPB)薄膜之有機薄膜電晶體(OTFTs), 它被發現在紫外光照射下所導致的退化能顯著減少。例如, 在大約紫外光照射120分鐘之後, 載子移動率的改變僅只37 % 並且臨限電壓值的變動是在10% 之內。相對地 , 沒有二氨基聯苯(NPB)薄膜的有機薄膜電晶體(OTFTs)遭受了嚴重的退化；載子移動率大約減少90%, 而臨限電壓值卻增加超過了40%。有機薄膜電晶體(OTFTs)因紫外光所導致的退化在此也被討論; 藉由原子力顯微鏡(AFM)的表面形態分析和電子顯微鏡的化學分析(ESCA)得知, 五環素(pentacene)薄膜表面的氧化和破壞是影響有機薄膜電晶體(OTFT)特性退化的主要因素。我們認為, 我們的二氨基聯苯(NPB) 保護層是一個有用的方法保護五環素有機薄膜電晶體(pentacene TFTs) 。

In this thesis, we fabricated N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl) benzidine (NPB) passivation to protect the organic thin-film transistors (OTFTs) from degradation under UV-light illumination. With a thermally-deposited NPB film on the OTFTs, it was found that UV-light induced degradation could be significantly reduced. For example, after about 120 minutes UV-light the change of field effect mobility was only 37 % and the change of threshold voltage was within 10%. On the contrary, the OTFTs without NPB film suffered serious degradation. The field-effect mobility was reduced by about 90%, and the threshold voltage was increased by more than 40%. UV-light induced degradation on OTFTs was also discussed; Through surface morphology analysis by atomic force microscopy ( AFM ) and electron Spectroscopy for Chemical Analysis ( ESCA ) , the surface oxidation and destroyed pentacene grains pentacene film was the dominative factor that influenced OTFT’s properties. We conclude that our NPB passivation is a promising way to protect pentacene TFTs. Finally, I would like to address that the work is conducted under the leading of my supervisor and also Mr. Kuo-His Yen, Ph. D student in our lab. The result is shared with all the co-workers in this research.