以聚乙二醇為添加物製作高效能負型有機薄膜電晶體

Abstract

本研究選用聚乙二醇，將其添加至負型[6,6]-phenyl C61-butyric acid methyl ester (PCBM) 有機薄膜電晶體之主動層中，研究其對元件特性之影響。由實驗結果可知添加適當比例之高分子量聚乙二醇能夠有效的提高元件效能並且表現出較好的穩定性。在本研究中，加入聚乙二醇之元件載子遷移率可由0.014 cm2/Vs 提升至0.044 cm2/Vs，而臨界電壓也可由17V縮小至-2V。在大氣環境下量測，未添加聚乙二醇之元件載子遷移率變為原本之千分之一，而添加聚乙二醇後則為十分之一。這可歸功於聚乙二醇分子與鋁電極產生化學反應，進而減少電子注入障礙。

This study investigates the effect of blending of poly(ethylene glycol) (PEG) into the active layer on the performance of n-channel organic thin-film transistors (OTFTs) based on [6,6]-phenyl C61-butyric acid methyl ester (PCBM). We found that the performance and the stability of the OTFTs could be enhanced after the addition of PEG. The mobility could be improved from 0.014 to 0.044 cm2/Vs, and the threshold voltage shifted from 17V toward to -2V. In the ambient conditions, the mobility of the pristine-PCBM device degraded by three orders. However, the one of the device prepared with PEG only decreased by one order. The enhancement could be attributed into the reduction of the electron injection barrier due to the chemical reactions between PEG molecules and Al atoms of the source/drain electrodes.