以蠶絲蛋白為閘極介電層之五苯環有機薄膜電晶體在不同相對濕度的特性

Characteristics of pentacene organic thin-film transistors with silk fibroin as gate dielectric at different humidity

唐御評(Yu-Ping Tang)

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

使用蠶絲蛋白作為閘極介電層，P-type有機半導體材料五苯環 ( pentacene ) 作為主動層的有機薄膜電晶體，有高子遷移率、低操作電壓的特性，但其特性受環境相對濕度影響，本論文使用封裝技術控制相對濕度，探討相對濕度對於有機薄膜電晶體的特性影響。在相對濕度為60%時電晶體擁有最佳的特性，其飽和區的載子遷移率約為16.8 cm2V-1s-1 、開關特性比約為1000倍；當相對濕度下降到30%時，其載子遷移率下降至約4 cm2V-1s-1，開關比特性下降至約100倍；當相對濕度上升到70%時，其載子遷移率下降至約0.28 cm2V-1s-1。由此可見電晶體的特性和相對濕度有密切關係。
電晶體的特性受相對濕度影響是由於閘極介電層的蠶絲蛋白薄膜電容因相對濕度改變而變化。在低相對濕度時，電容值稍微上升；當相對濕度介於40%~60%時，電容值有明顯的上升，此與電晶體的特性提升有關；當相對濕度超過60%，其電容劇烈上升，卻降低電晶體的特性。

關鍵字

有機薄膜電晶體 ； 五苯環 ； 封裝 ； 相對濕度 ； 蠶絲蛋白

並列摘要

Device characteristics of pentacene organic thin-film transistors ( OTFTs ) with silk fibroin as gate dielectric vary with relative humidity in air ambient. An encapsulation method has been developed to keep OTFTs at a fixed relative humidity. At ca. 60% relative humidity, the OTFTs exhibit a best field-effect mobility value of ca. 16.8 cm2V-1s-1 in the saturation regime and an on/off ratio of approximately three orders of magnitudes. When the relative humidity decreases to ca. 30%, filed-effect mobility decreases to ca. 4 cm2V-1s-1 and the on/off ratio reduces to approximately two orders of magnitudes. When the relative humidity increases to ca. 70%, filed-effect mobility decreases to ca. 0.28 cm2V-1s-1 and capacitance sharply increases. Device characteristics of the OTFTs depend on relative humidity.
The humidity dependence of device characteristics is attributed to the change of capacitance of silk fibroin gate dielectric at different relative humidity. In the low humidity regime, quasi-static capacitance increases slowly with relative humidity. When relative humidity is about 40%~60%, quasi-static capacitance increases rapidly with relative humidity, which is strongly correlated to the better device performance at this relative humidity. When relative humidity is higher than 60%, the quasi-static capacitance extremely increases with relative humidity and decreases device performance.

並列關鍵字

OTFT ； pentacene ； encapsulation ； relative humidity ； silk fibroin

參考文獻

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