有機無機電晶體應用於氣體感測之研究

Organic and Inorganic Transistors for Gas Sensing

余治寬(Chih-Kuan Yu)

指導教授 ： 冉曉雯 ； 蔡娟娟

國立交通大學/電機學院/光電工程系所/碩士(2012年)

https://doi.org/10.6842/NCTU.2012.00412

摘要

在本研究中，我們首先將介紹一個有機垂直通道空間電荷限制電晶體的氣體感測器。透過具備氧化或還原特性的氣體對電晶體的主動層造成電子摻雜或電子解摻雜的效應，進而改變垂直通道中的電位分佈，導致輸出電流密度的改變。藉由對於氨氣具備30 ppb的感測極限，此氣體感測器將可以應用在被非侵入式呼氣監控的定點照護檢驗。
此外，一個無機非晶銦鎵鋅氧化物薄膜電晶體混合式氣體感測器也將被介紹。我們將金屬氧化物半導體覆蓋在電晶體的背通道上面，作為氣體感測層以及第二個閘極。透過接觸具備氧化或還原特性的氣體分子，電荷將會在感測層和氣體分子間傳遞，造成感測層的位能改變，使得第二個閘極的電位改變，導致輸出電流改變。此無機混合式氣體感測器對於氨氣和一氧化氮的感測極限分別為50 ppb和3ppm。
最後，我們將在附錄中介紹提升非晶銦鎵鋅氧化物薄膜電晶體載子遷移率的初步結果。透過使用飛秒雷射照射非晶銦鎵鋅氧化物薄膜表面，我們可以得到一個高載子遷移率(~84 cm2/Vs)的電晶體。其可能原因為，飛秒雷射照射非晶銦鎵鋅氧化物薄膜後，會造成通道導電率的提升，進而使得載子遷移率提升。

關鍵字

有機電晶體 ； 無機電晶體 ； 氣體感測器 ； 銦鎵鋅氧化物 ； 氨氣 ； 一氧化氮

並列摘要

In this thesis, we report a very sensitive gas sensor embedded in a vertical polymer space-charge-limited transistor at first. The oxidizing and reducing gases act as electron dedoping and electron doping agents on the transistor active layer to change the potential distribution in the vertical channel and hence to change the output current density. With a 30-ppb detection limit to ammonia, the sensor can be used for non-invasive breath monitor in point-of-care applications.
In addition, a metal-oxide sensing layer is capped onto an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) to form a hybrid sensor. The metal-oxide layer, served as a second gate, forms a p-n junction with a-IGZO film. Oxidizing or reducing vapor molecules act like electron acceptors or electron donors to change the potential of the metal-oxide layer and the current of a-IGZO TFT. A sensitive response to 50 ppb ammonia and 3 ppm nitric oxide is obtained.
In the end, a preliminary result of femtosecond laser irradiation (FLI) on a-IGZO TFTs is demonstrated in appendix. A high mobility (~84 cm2/Vs) top-gate (TG) a-IGZO TFT is proposed. It is supposed that FLI on a-IGZO film induces an increase in channel conductivity and forms a high field-effect mobility (~84 cm2/Vs) TG a-IGZO TFT.

並列關鍵字

organic transistor ； inorganic transistor ； gas sensor ； IGZO ； Ammonia ； Nitric oxide

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