Organic and Inorganic Transistors for Gas Sensing

• Main Authors: Yu, Chih-Kuan, 余治寬
• Other Authors: Zan, Hsiao-Wen
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/71242579474447761289

碩士 === 國立交通大學 === 光電工程學系 === 100 === 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.