本研究使用溶液式高介電材料鋯鈦酸鋇於五環素有機薄膜電晶體，相較於金屬遮罩，透過黃光微影能夠有效將元件面積縮減。為了降低臨界電壓，電晶體的閘極使用兩種不同功函數金屬，分別為較高與較低於五環素的HOMO，發現藉由利用較高的功函數金屬，臨界電壓有效從-4.6V下降至-2.6V。並且使用紫外光/臭氧處理元件之源極與汲極表面，進而改善五環素分子於金屬表面失序成長之現象，增強電流注入能力，同時降低電晶體之總電阻。並且透過AFM與XRD分析，得知五環素分子成長於紫外光/臭氧處理之金屬表面之晶粒與晶相明顯得到改善，因此得到良好之電晶體特性：高場效載子移動率（4.5 cm2V-1s-1)、低次臨界效應（260 mV/decade)、高電流開關比（1.4 × 105)以及低驅動電壓(-5V)。

The solution-processed high-k barium zirconate titanate (BZT) as gate dielectric for pentacene-based organic thin film transistor (OTFT) applications is presented. As compared to the conventional metal mask, the fabricated transistors by photolithography process can effectively reduce the device dimension, especially for the bottom gate contact structures. To reduce the transistor threshold voltage, higher work function metals (Au) is used as the gate electrodes. The threshold voltage is efficiently decreased from -4.6 to -2.6 V as compared to that of Al. In addition, the UV/ozone was employed to treat the Au(source/drain) surface to improve the poor crystalline of pentacene grown on Au. Moreover, the surface morphologies and orientations of pentacene films were analyzed through atomic force microscopy (AFM) and X-ray diffraction. As the results show, the stack of pentacene molecules from disorder changed to vertical growth on the Au surface. Thus, the electrical properties of pentacene-based thin film transistors show high field-effect mobility of 4.5 cm2V-1s-1, low subthreshold swing of 260 mV/decade, high on/off ratio of 1.4× 105 and low operation voltage of -5 V. These results are better than the reported data using bottom contact pentacene OTFTs.

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