在本論文中，我們研製一系列之半導體氣體感測器以及其後端感測電路系統，並探討在不同溫度的元件電性以及氣體感測特性，除了研究半導體式氣體感測器元件在不同溫度下的感測效能外，在未來更可探討不同感測材料對於氣體感測特性之影響。
首先，我們研製並探討(金屬-半導體) 鈀/氮化鋁鎵異質結構場效電晶體式氫氣感測器之氫氣感測特性。該元件展現了高靈敏度、極低的偵檢極限以及快速的響應時間優點。另外由於氮化鋁鎵材料系列的特性，該元件在操作溫度高達300oC依然能維持良好的氣體感測特性，而該感測器元件同時展現極低的氫氣氣體偵檢濃度能力(≦1 ppm H2/air)。
而當元件置放於氮氣氣氛下，感測器對於氫氣濃度展現相當優異的感測特性(≤ 10 ppb H2/N2)，綜合以上實驗結果發現，本研製感測器元件具高性能氣體感測特性，以及高溫操作能力，而且製程方式與微機電系統製程相容，本研究之感測元件在高效能感測器與微機電系統整合方面極具潛力。
其次，我們研製一銦錫氧化物氨氣氣體感測器，並探討其相關氨氣感測特性。銦錫氧化物對於氨氣具有良好之觸媒活性，因此，可使用於檢測氨氣之感測材料。根據實驗結果發現良好的操作溫度為150oC，並且可偵檢之氨氣氣體濃度範圍廣泛。而在本研製元件中加入銦錫氧化物/金之製程變化，跟一般銦錫氧化物氣體感測器相比較，本研製元件展現極其優異以及明顯的氣體感測特性變化。因此，本元件呈現良好之感測效能，更具備須高性能氨氣氣體感測能力應用之潛力。
接者，由於氣體感測器訊號輸出難以辨認以及應用，因此，在本研究中，針對氫氣感測器元件開發一具無線傳輸能力之氣體感測系統。並且在處理感測訊號中應用新開發之灰色多項式差別演算法(GPDM)進行相關訊號處理以及用以降低在傳輸過程中大量訊號造成的系統負載。根據實驗結果，本系統展現容易操作、高氣體感測性能、可攜性以及遠端傳輸能力之優點。另外由於酸鹼值在相關化學產業中為一重要參數，因此，本研究另外針對酸鹼值感測器開發一簡易之酸鹼值感測系統。所使用為氧化鎳薄膜所製作之酸鹼值感測元件，本元件具備酸鹼值濃度pH2到pH12範圍內的感測能力。針對酸鹼值感測器元件所開發之感測系統，展現其相關濃度變化之讀出以及顯示能力。根據系統實驗數據結果，本研製之酸鹼值感測系統展現其結構簡單、低成本、容易操作以及高可攜性等相關優點。

In this dissertation, the semiconductor type gas sensors and related sensing circuits are fabricated and studied. The electrical characteristics and gas-sensing performance of the sensors are investigated at different temperatures. Furthermore, the influence of gate sensing material on the sensing performance of each sensing device is studied.
First, the hydrogen-sensing characteristics of Pd/AlGaN/GaN heterostructure field-effect transistor (HFET) hydrogen sensors is fabricated and studied. The studied device shows advantages of high sensitivity, low detection limit, and fast response. Based on the inherent advantages of AlGaN/GaN material system, the good hydrogen sensing performance is observed even the operation temperature is elevated to 523K. Also, this device exhibits remarkable sensing ability under a very low hydrogen concentration level (≦1 ppm H2/air). In addition, this studied device exhibits good and stable hydrogen sensing properties even at an extremely low hydrogen concentration ambience (≤ 10 ppb H2/N2) under a nitrogen ambience. Therefore, the studied sensing device provides the promise for high-performance, high-temperature electronics and micro electro-mechanical system (MEMS) applications.
Second, the ammonia-sensing characteristics of an ITO-based ammonia gas sensor is fabricated and studied. The ITO semiconductor material shows high catalytic activity to ammonia gas. It is, therefore, used as the sensing material for ammonia detection. The optimal operation temperature of the studied ITO-Au sensor is 150oC. Good ammonia sensing performance over widespread ammonia gas concentration regime of the studied ITO-Au sensor is obtained. The sensitivity ratio of the studied ITO-Au sensor is higher than that of the ITO sensor one. The enhanced sensing performance of the studied ITO-Au sensor is mainly due to the rougher surface which causes more effective adsorption areas. Thus, the studied sensor presents advantages of simple structure, ease of fabrication, high sensing performance, extremely low ammonia-gas limit of detection (LOD), and low temperature operation capability. Consequently, the studied sensor shows a promise for high-performance ammonia-gas sensing applications.
Finally, due to the sensing signal of hydrogen gas sensor device is difficult to identify and recognize. In this work, a wireless hydrogen sensing system is successfully developed and demonstrated. In addition, a GPDM method is used to effectively reduce the redundant hydrogen sensing data for alleviating the transmission load. A remote transmission (d > 50m in distance) of hydrogen sensing signals from a wireless transmission unit to a remote monitor has been successfully achieved. Thus, the studied hydrogen sensing system exhibits a promise of high hydrogen sensing performance, easy operation, high portability, and significant wireless transmission capability. In addition, the pH value is an important factor in many industrial fields. Hence, in this work, a pH value sensing system is successfully developed and demonstrated. The sensing characteristics of the nickel oxide (NiO) membrane are stable in pH solutions between pH2 and pH12. From those experimental results, this studied pH value sensing system demonstrates advantages of simple pH sensing system architecture, low cost, easy operation, and high portability.

[1]L. Barreto, A. Makihira, and K. Riahi, "The hydrogen economy in the 21st century: a sustainable development scenario," International Journal of Hydrogen Energy, vol. 28, pp. 267-284, Mar 2003.
[2]W. P. Xiao, Y. Z. Cheng, W. J. Lee, V. Chen, and S. Charoensri, "Hydrogen filling station design for fuel cell vehicles," IEEE Transactions on Industry Applications, vol. 47, pp. 245-251, Jan-Feb 2011.
[3]C. C. Chan, "The state of the art of electric and hybrid vehicles," Proceedings of the Ieee, vol. 90, pp. 247-275, Feb 2002.
[4]S. Nakagomi, K. Okuda, and Y. Kokubun, "Electrical properties dependent on H2 gas for new structure diode of Pt-thin WO3-SiC," Sensors and Actuators B-Chemical, vol. 96, pp. 364-371, Nov 2003.
[5]N. Van Hieu, N. Q. Dung, P. D. Tam, T. Trung, and N. D. Chien, "Thin film polypyrrole/SWCNTs nanocomposites-based NH3 sensor operated at room temperature," Sensors and Actuators B-Chemical, vol. 140, pp. 500-507, Jul 2009.
[6]Z. Ling, C. Leach, and R. Freer, "Heterojunction gas sensors for environmental NO2 and CO2 monitoring," Journal of the European Ceramic Society, vol. 21, pp. 1977-1980, 2001.
[7]S. R. Morrison, "Semiconductor gas sensors," Sensors and Actuators, vol. 2, pp. 329-341, 1982.
[8]G. F. Fine, L. M. Cavanagh, A. Afonja, and R. Binions, "Metal oxide semi-conductor gas sensors in environmental monitoring," Sensors, vol. 10, pp. 5469-5502, Jun 2010.
[9]T. H. Tsai, H. I. Chen, K. W. Lin, C. W. Hung, C. H. Hsu, T. P. Chen, L. Y. Chen, K. Y. Chu, C. F. Chang, and W. C. Liu, "Hydrogen sensing characteristics of a Pd/AlGaN/GaN Schottky diode," Applied Physics Express, vol. 1, p. 041102, Apr 2008.
[10]S. Y. Chiu, H. W. Huang, K. C. Liang, T. H. Huang, K. P. Liu, J. H. Tsai, and W. S. Lour, "High sensing response Pd/GaN hydrogen sensors with a porous-like mixture of Pd and SiO2," Semiconductor Science and Technology, vol. 24, p. 045007, Apr 2009.
[11]S. Y. Chiu, J. H. Tsai, H. W. Huang, K. C. Liang, T. H. Huang, K. P. Liu, T. M. Tsai, K. Y. Hsu, and W. S. Lour, "Hydrogen sensors with double dipole layers using a Pd-mixture-Pd triple-layer sensing structure," Sensors and Actuators B-Chemical, vol. 141, pp. 532-537, Sep 2009.
[12]W. C. Liu, H. J. Pan, H. I. Chen, K. W. Lin, S. Y. Cheng, and K. H. Yu, "Hydrogen-sensitive characteristics of a novel Pd/InP MOS Schottky diode hydrogen sensor," IEEE Transactions on Electron Devices, vol. 48, pp. 1938-1944, Sep 2001.
[13]J. R. Huang, W. C. Hsu, Y. J. Chen, T. B. Wang, H. I. Chen, and W. C. Liu, "Investigation of hydrogen-sensing characteristics of a Pd/GaN Schottky diode," Ieee Sensors Journal, vol. 11, pp. 1194-1200, May 2011.
[14]S. W. Tan, J. H. Tsai, S. W. Lai, C. Lo, and W. S. Lour, "Hydrogen-sensitive sensor with stabilized Pd-mixture forming sensing nanoparticles on an interlayer," International Journal of Hydrogen Energy, vol. 36, pp. 15446-15454, Nov 2011.
[15]C. H. Huang, J. H. Tsai, T. M. Tsai, K. Y. Hsu, W. C. Yang, H. W. Huang, and W. S. Lour, "Hydrogen sensor with Pd nanoparticles upon an interfacial layer with oxygen," Applied Physics Express, vol. 3, p. 075001, 2010.
[16]F. R. Juang, H. Y. Chiu, Y. K. Fang, K. H. Cho, and Y. C. Chen, "An n-SnOx/i-diamond/p-diamond diode with nanotip structure for high-temperature CO sensing applications," Ieee Transactions on Electron Devices, vol. 59, pp. 1786-1791, Jun 2012.
[17]Y. Shimizu, A. Jono, T. Hyodo, and M. Egashira, "Preparation of large mesoporous SnO2 powder for gas sensor application," Sensors and Actuators B-Chemical, vol. 108, pp. 56-61, Jul 2005.
[18]A. Arbab, A. Spetz, and I. Lundström, "Gas sensors for high-temperature operation based on metal-oxide-silicon carbide (MOSIC) devices," Sensors and Actuators B-Chemical, vol. 15, pp. 19-23, Aug 1993.
[19]C. Lu, Z. Chen, and K. Saito, "Hydrogen sensors based on Ni/SiO2/Si MOS capacitors," Sensors and Actuators B-Chemical, vol. 122, pp. 556-559, Mar 2007.
[20]I. Lundström, S. Shivaraman, C. Svensson, and L. Lundkvist, "Hydrogen-sensitive MOS field-effect transistor," Applied Physics Letters, vol. 26, pp. 55-57, 1975.
[21]Y. J. Liu, C. C. Huang, T. Y. Chen, C. S. Hsu, J. K. Liou, and W. C. Liu, "Improved performance of an InGaN-based light-emitting diode with a p-GaN/n-GaN barrier junction," IEEE Journal of Quantum Electronics, vol. 47, pp. 755-761, Jun 2011.
[22]T. B. Wang, W. C. Hsu, J. L. Su, R. T. Hsu, Y. H. Wu, Y. S. Lin, and K. H. Su, "Comparison of Al0.32Ga0.68N/GaN heterostructure field-effect transistors with different channel thicknesses," Journal of the Electrochemical Society, vol. 154, pp. H131-H133, 2007.
[23]Y. J. Liu, C. C. Huang, T. Y. Chen, C. S. Hsu, T. Y. Tsai, and W. C. Liu, "On a GaN-based light-emitting diode with an indium-tin-oxide (ITO) direct-Ohmic contact structure," IEEE Photonics Technology Letters, vol. 23, pp. 1037-1039, Aug 2011.
[24]I. Saidi, Y. Cordier, M. Chmielowska, H. Mejri, and H. Maaref, "Thermal effects in AlGaN/GaN/Si high electron mobility transistors," Solid-State Electronics, vol. 61, pp. 1-6, Jul 2011.
[25]L. Yuan, H. W. Chen, and K. J. Chen, "Normally off AlGaN/GaN metal-2DEG tunnel-junction field-effect transistors," IEEE Electron Device Letters, vol. 32, pp. 303-305, Mar 2011.
[26]S. Arulkumaran, G. I. Ng, Z. H. Liu, and C. H. Lee, "High temperature power performance of AlGaN/GaN high-electron-mobility transistors on high-resistivity silicon," Applied Physics Letters, vol. 91, Aug 2007.
[27]H. Lu, P. Sandvik, A. Vertiatchikh, J. Tucker, and A. Elasser, "High temperature Hall effect sensors based on AlGaN/GaN heterojunctions," Journal of Applied Physics, vol. 99, Jun 2006.
[28]T. H. Tsai, H. I. Chen, K. W. Lin, Y. W. Kuo, C. F. Chang, C. W. Hung, L. Y. Chen, T. P. Chen, Y. C. Liu, and W. C. Liu, "SiO2 passivation effect on the hydrogen adsorption performance of a Pd/AlGaN-based Schottky diode," Sensors and Actuators B-Chemical, vol. 136, pp. 338-343, Mar 2009.
[29]W. J. Buttner, M. B. Post, R. Burgess, and C. Rivkin, "An overview of hydrogen safety sensors and requirements," International Journal of Hydrogen Energy, vol. 36, pp. 2462-2470, Feb 2011.
[30]S. Joo, I. Muto, and N. Hara, "Hydrogen gas sensor using Pt- and Pd-added anodic TiO2 nanotube films," Journal of the Electrochemical Society, vol. 157, pp. J221-J226, 2010.
[31]Y. Nakamura, H. X. Zhuang, A. Kishimoto, O. Okada, and H. Yanagida, "Enhanced CO and CO2 gas sensitivity of the CuO/ZnO heterocontact made by quenched CuO ceramics," Journal of the Electrochemical Society, vol. 145, pp. 632-638, Feb 1998.
[32]M. Stankova, X. Vilanova, J. Calderer, E. Llobet, J. Brezmes, I. Gracia, C. Cane, and X. Correig, "Sensitivity and selectivity improvement of rf sputtered WO3 microhotplate gas sensors," Sensors and Actuators B-Chemical, vol. 113, pp. 241-248, Jan 2006.
[33]A. Dutta, N. Kaabbuathong, M. L. Grilli, E. Di Bartolomeo, and E. Traversa, "Study of YSZ-based electrochemical sensors with WO3 electrodes in NO2 and CO environments," Journal of the Electrochemical Society, vol. 150, pp. H33-H37, Feb 2003.
[34]H. Mbarek, M. Saadoun, and B. Bessais, "Screen-printed Tin-doped indium oxide (ITO) films for NH3 gas sensing," Materials Science & Engineering C-Biomimetic and Supramolecular Systems, vol. 26, pp. 500-504, Mar 2006.
[35]E. Aperathitis, M. Bender, V. Cimalla, G. Ecke, and M. Modreanu, "Properties of rf-sputtered indium-tin-oxynitride thin films," Journal of Applied Physics, vol. 94, pp. 1258-1266, Jul 2003.
[36]H. J. Chang, W. F. Chen, K. M. Huang, C. L. Ho, and M. C. Wu, "Deposition of transparent indium molybdenum oxide thin films and the application for organic solar cells," Japanese Journal of Applied Physics, vol. 51, Feb 2012.
[37]J. Jiang, J. Sun, W. Dou, and Q. Wan, "Junctionless flexible oxide-based thin-film transistors on paper substrates," Ieee Electron Device Letters, vol. 33, pp. 65-67, Jan 2012.
[38]Z. Jiao, M. H. Wu, J. Z. Gu, and X. L. Sun, "The gas sensing characteristics of ITO thin film prepared by sol-gel method," Sensors and Actuators B-Chemical, vol. 94, pp. 216-221, Sep 2003.
[39]A. Salehi and A. Nikfarjam, "Room temperature carbon monoxide sensor using ITO/n-GaAs Schottky contact," Sensors and Actuators B-Chemical, vol. 101, pp. 394-400, Jul 2004.
[40]K. S. Yoo, S. H. Park, and J. H. Kang, "Nano-grained thin-film indium tin oxide gas sensors for H2 detection," Sensors and Actuators B-Chemical, vol. 108, pp. 159-164, Jul 2005.
[41]Z. Jiao, M. H. Wu, Z. Qin, M. H. Lu, and J. Z. Gu, "The NO2 sensing ITO thin films prepared by ultrasonic spray pyrolysis," Sensors, vol. 3, pp. 285-289, Aug 2003.
[42]B. Timmer, W. Olthuis, and A. van den Berg, "Ammonia sensors and their applications - a review," Sensors and Actuators B-Chemical, vol. 107, pp. 666-677, Jun 2005.
[43]A. K. Seferlis and S. G. Neophytides, "Photoelectrocatalytic electricity and/or H2 production from alcohols: The effect of TiO2 film thickness," Journal of the Electrochemical Society, vol. 158, pp. H183-H189, 2011.
[44]M. Conte, A. Iacobazzi, M. Ronchetti, and R. Vellone, "Hydrogen economy for a sustainable development: state-of-the-art and technological perspectives," Journal of Power Sources, vol. 100, pp. 171-187, Nov 2001.
[45]Y. Cai, Z. Q. Cheng, W. C. W. Tang, K. M. Lau, and K. J. Chen, "Monolithically integrated enhancement/depletion-mode AlGaN/GaN HEMT inverters and ring oscillators using CF4 plasma treatment," Ieee Transactions on Electron Devices, vol. 53, pp. 2223-2230, Sep 2006.
[46]C. F. Lo, C. Y. Chang, B. H. Chu, S. J. Pearton, A. Dabiran, P. P. Chow, and F. Ren, "Effect of humidity on hydrogen sensitivity of Pt-gated AlGaN/GaN high electron mobility transistor based sensors," Applied Physics Letters, vol. 96, p. 232106, Jun 2010.
[47]S. Y. Chiu, H. W. Huang, T. H. Huang, K. C. Liang, K. P. Liu, J. H. Tsai, and W. S. Lour, "Comprehensive study of Pd/GaN metal-semiconductor-metal hydrogen sensors with symmetrically bi-directional sensing performance," Sensors and Actuators B-Chemical, vol. 138, pp. 422-427, May 2009.
[48]T. H. Tsai, H. I. Chen, K. W. Lin, T. Y. Chen, C. C. Huang, K. S. Hsu, and W. C. Liu, "A hydrogen sensor based on a metamorphic high electron mobility transistor (MHEMT)," Microelectronics Reliability, vol. 50, pp. 734-737, May 2010.
[49]J. H. Lee, "High-power InGaN-based LED with tunneling-junction-induced two-dimensional electron gas at AlGaN/GaN heterostructure," IEEE Transactions on Electron Devices, vol. 58, pp. 3058-3064, Sep 2011.
[50]G. D. Zeiss, W. J. Meath, J. C. F. Macdonald, and D. J. Dawson, "Additivity of atomic and molecular dipole properties and dispersion energies using H, N, O, H2, N2, O2, NO, N2O, NH3 and H2O as models," Molecular Physics, vol. 39, pp. 1055-1072, 1980.
[51]W. S. Lour, M. K. Tsai, K. C. Chen, Y. W. Wu, S. W. Tan, and Y. J. Yang, "Dual-gate In0.5Ga0.5P/In0.2Ga0.8As pseudomorphic high electron mobility transistors with high linearity and variable gate-voltage swing," Semiconductor Science and Technology, vol. 16, pp. 826-830, Oct 2001.
[52]D. Soderberg and I. Lundstrom, "Competition between hydrogen and oxygen dissociation on palladium surfaces at atmospheric pressures," Solid State Communications, vol. 45, pp. 431-434, 1983.
[53]T. Kobiela and R. Dus, "STM/AFM studies of the catalytic reaction of oxygen with hydrogen on the surface of thin palladium film," Vacuum, vol. 63, pp. 267-276, Jul 2001.
[54]T. H. Tsai, H. I. Chen, K. W. Lin, Y. W. Kuo, P. S. Chiu, C. F. Chang, L. Y. Chen, T. P. Chen, Y. J. Liu, and W. C. Liu, "On a Pd/InAlAs metamorphic high electron mobility transistor (MHEMT)-based hydrogen sensor," Sensors and Actuators B-Chemical, vol. 139, pp. 310-316, Jun 2009.
[55]C. F. Chang, T. H. Tsai, H. I. Chen, K. W. Lin, T. P. Chen, L. Y. Chen, Y. C. Liu, and W. C. Liu, "Hydrogen sensing properties of a Pd/SiO2/AlGaN-based MOS diode," Electrochemistry Communications, vol. 11, pp. 65-67, Jan 2009.
[56]L. M. Lechuga, A. Calle, D. Golmayo, P. Tejedor, and F. Briones, "A new hydrogen sensor based on a Pt/GaAs Schottky diode," Journal of the Electrochemical Society, vol. 138, pp. 159-162, Jan 1991.
[57]J. R. Huang, W. C. Hsu, Y. J. Chen, T. B. Wang, K. W. Lin, H. I. Chen, and W. C. Liu, "Comparison of hydrogen sensing characteristics for Pd/GaN and Pd/Al0.3Ga0.7As Schottky diodes," Sensors and Actuators B-Chemical, vol. 117, pp. 151-158, Sep 2006.
[58]K. W. Lin and R. H. Chang, "Comprehensive study of pseudomorphic high electron mobility transistor (pHEMT)-based hydrogen sensor," Sensors and Actuators B-Chemical, vol. 119, pp. 47-51, Nov 2006.
[59]Y. Y. Tsai, K. W. Lin, H. I. Chen, C. W. Hung, T. P. Chen, T. H. Tsai, L. Y. Chen, K. Y. Chu, and W. C. Liu, "Comprehensive study of a Pd/Al0.24Ga0.76As-based field-effect-transistor-type hydrogen sensor," Sensors and Actuators B-Chemical, vol. 133, pp. 128-134, Jul 2008.
[60]H. I. Chen, Y. I. Chou, and C. Y. Chu, "A novel high-sensitive Pd/InP hydrogen sensor fabricated by electroless plating," Sensors and Actuators B-Chemical, vol. 85, pp. 10-18, Jun 2002.
[61]W. C. Hsu, C. S. Lee, C. S. Ho, Y. N. Lai, J. C. Huang, B. Y. Chou, A. Y. Kao, H. H. Yeh, and C. L. Wu, "InAlAs/InGaAs MOS-MHEMTs by using ozone water oxidation treatment," Electrochemical and Solid State Letters, vol. 13, pp. H234-H236, 2010.
[62]S. Y. Cheng, "Very wide current-regime operation of an InP/InGaAs tunneling emitter bipolar transistor (TEBT)," Microelectronics Reliability, vol. 47, pp. 1208-1212, Aug 2007.
[63]T. H. Tsai, J. R. Huang, K. W. Lin, W. C. Hsu, H. I. Chen, and W. C. Liu, "Improved hydrogen sensing characteristics of a Pt/SiO2/GaN Schottky diode," Sensors and Actuators B-Chemical, vol. 129, pp. 292-302, Jan 2008.
[64]Y. Y. Tsai, K. W. Lin, H. I. Chen, I. P. Liu, C. W. Hung, T. P. Chen, T. H. Tsai, L. Y. Chen, K. Y. Chu, and W. C. Liu, "Transient response of a transistor-based hydrogen sensor," Sensors and Actuators B-Chemical, vol. 134, pp. 750-754, Sep 2008.
[65]C. W. Hung, K. W. Lin, R. C. Liu, Y. Y. Tsai, P. H. Lai, S. I. Fu, T. P. Chen, H. I. Chen, and W. C. Liu, "On the hydrogen sensing properties of a Pd/GaAs transistor-type gas sensor in a nitrogen ambiance," Sensors and Actuators B-Chemical, vol. 125, pp. 22-29, Jul 2007.
[66]C. W. Hung, T. H. Tsai, H. I. Chen, Y. Y. Tsai, T. P. Chen, and W. C. Liu, "Further investigation of a hydrogen-sensing Pd/GaAs heterostructure field-effect transistor (HFET)," Sensors and Actuators B-Chemical, vol. 132, pp. 587-592, Jun 2008.
[67]T. Y. Chen, H. I. Chen, C. C. Huang, C. S. Hsu, P. S. Chiu, P. C. Chou, R. C. Liu, and W. C. Liu, "Hydrogen-sensing characteristics of a Pd/GaN Schottky diode with a simple surface roughness approach," Ieee Transactions on Electron Devices, vol. 58, pp. 4079-4086, Nov 2011.
[68]P. F. Ruths, S. Ashok, and S. J. Fonash, "A study of Pd-Si mis Schottky-barrier diode hydrogen detector," Ieee Transactions on Electron Devices, vol. 28, pp. 1003-1009, 1981.
[69]B. S. Kang, F. Ren, B. P. Gila, C. R. Abernathy, and S. J. Pearton, "AlGaN/GaN-based metal-oxide-semiconductor diode-based hydrogen gas sensor," Applied Physics Letters, vol. 84, pp. 1123-1125, Feb 2004.
[70]J. H. Song, W. Lu, J. S. Flynn, and G. R. Brandes, "Pt-AlGaN/GaN Schottky diodes operated at 800 degrees C for hydrogen sensing," Applied Physics Letters, vol. 87, Sep 2005.
[71]J. H. Song and W. Lu, "Operation of Pt/AlGaN/GaN-heterojunction field-effect-transistor hydrogen sensors with low detection limit and high sensitivity," Ieee Electron Device Letters, vol. 29, pp. 1193-1195, Nov 2008.
[72]K. S. Kim and G. S. Chung, "Fast response hydrogen sensors based on palladium and platinum/porous 3C-SiC Schottky diodes," Sensors and Actuators B-Chemical, vol. 160, pp. 1232-1236, Dec 2011.
[73]Y. Shimizu, T. Okamoto, Y. Takao, and M. Egashira, "Desorption behavior of ammonia from TiO2-based specimens - ammonia sensing mechanism of double-layer sensors with TiO2-based catalyst layers," Journal of Molecular Catalysis a-Chemical, vol. 155, pp. 183-191, Apr 2000.
[74]T. Hyodo, H. Shibata, Y. Shimizu, and M. Egashira, "H2 sensing properties of diode-type gas sensors fabricated with Ti- and/or Nb-based materials," Sensors and Actuators B-Chemical, vol. 142, pp. 97-104, Oct 2009.
[75]C. Ishibashi, T. Hyodo, Y. Shimizu, and M. Egashira, "H2S sensing properties of macroporous In2O3-based sensors," Sensor Letters, vol. 9, pp. 369-373, Feb 2011.
[76]J. X. Wang, X. W. Sun, Y. Yang, H. Huang, Y. C. Lee, O. K. Tan, and L. Vayssieres, "Hydrothermally grown oriented ZnO nanorod arrays for gas sensing applications," Nanotechnology, vol. 17, pp. 4995-4998, Oct 2006.
[77]J. Zhang, H. F. Zhu, L. Zhang, C. A. Di, W. Xu, W. P. Hu, Y. Q. Liu, and D. B. Zhu, "Organic field-effect transistors based on low-temperature processable transparent polymer dielectrics with low leakage current," Organic Electronics, vol. 13, pp. 733-736, May 2012.
[78]N. L. Hung, H. Kim, S. K. Hong, and D. Kim, "Enhancement of CO gas sensing properties in ZnO thin films deposited on self-assembled Au nanodots," Sensors and Actuators B-Chemical, vol. 151, pp. 127-132, Nov 2010.
[79]Y. J. Li, R. Duan, P. B. Shi, and G. G. Qin, "Synthesis of ZnO nanoparticles on Si substrates using a ZnS source," Journal of Crystal Growth, vol. 260, pp. 309-315, Jan 2004.
[80]C. W. Lin, H. I. Chen, T. Y. Chen, C. C. Huang, C. S. Hsu, R. C. Liu, and W. C. Liu, "On an indium-tin-oxide thin film based ammonia gas sensor," Sensors and Actuators B-Chemical, vol. 160, pp. 1481-1484, Dec 2011.
[81]C. W. Lin, H. I. Chen, T. Y. Chen, C. C. Huang, C. S. Hsu, and W. C. Liu, "Ammonia sensing characteristics of sputtered indium tin oxide (ITO) thin films on quartz and sapphire substrates," Ieee Transactions on Electron Devices, vol. 58, pp. 4407-4413, Dec 2011.
[82]M. Takata, D. Tsubone, and H. Yanagida, "Dependence of electrical conductivity of ZnO on degree of sintering," Journal of the American Ceramic Society, vol. 59, pp. 4-8, 1976.
[83]R. Glemza and R. J. Kokes, "Transient species in oxygen take-up by zinc oxide," The Journal of Physical Chemistry, vol. 66, pp. 566-568, 1962/03/01 1962.
[84]K. K. Makhija, A. Ray, R. M. Patel, U. B. Trivedi, and H. N. Kapse, "Indium oxide thin film based ammonia gas and ethanol vapour sensor," Bulletin of Materials Science, vol. 28, pp. 9-17, Feb 2005.
[85]A. Z. Sadek, S. Choopun, W. Wlodarski, S. J. Ippolito, and K. Kalantar-zadeh, "Characterization of ZnO nanobelt-based gas sensor for H2, NO2, and hydrocarbon sensing," Ieee Sensors Journal, vol. 7, pp. 919-924, May-Jun 2007.
[86]H. S. Gu, Z. Wang, and Y. M. Hu, "Hydrogen gas sensors based on semiconductor oxide nanostructures," Sensors, vol. 12, pp. 5517-5550, May 2012.
[87]J. N. Tiwari, R. N. Tiwari, and K. S. Kim, "Zero-dimensional, one-dimensional, two-dimensional and three-dimensional nanostructured materials for advanced electrochemical energy devices," Progress in Materials Science, vol. 57, pp. 724-803, May 2012.
[88]S. Y. Chiu, H. W. Huang, K. C. Liang, T. H. Huang, K. P. Liu, J. H. Tsai, and W. S. Lour, "GaN hydrogen sensor with Pd-SiO2 mixture forming sensing nanoparticles," Electronics Letters, vol. 45, pp. 231-232, Feb 2009.
[89]S. Y. Chiu, H. W. Huang, T. H. Huang, K. C. Liang, K. P. Liu, J. H. Tsai, and W. S. Lour, "Comprehensive investigation on planar type of Pd-GaN hydrogen sensors," International Journal of Hydrogen Energy, vol. 34, pp. 5604-5615, Jul 2009.
[90]P. Kar, N. C. Pradhan, and B. Adhikari, "Ammonia sensing by hydrochloric acid doped poly(m-aminophenol)-silver nanocomposite," Journal of Materials Science, vol. 46, pp. 2905-2913, May 2011.
[91]H. Jin, Y. Xu, R. Lin, and W. Han, "A proposal for a novel multi-functional energy system for the production of hydrogen and power," International Journal of Hydrogen Energy, vol. 33, pp. 9-19, Jan 2008.
[92]K. I. Lundstrom, M. S. Shivaraman, and C. M. Svensson, "Hydrogen-sensitive Pd-gate MOS transistor," Journal of Applied Physics, vol. 46, pp. 3876-3881, 1975.
[93]Z. Zhao, M. A. Carpenter, H. Xia, and D. Welch, "All-optical hydrogen sensor based on a high alloy content palladium thin film," Sensors and Actuators B-Chemical, vol. 113, pp. 532-538, Jan 17 2006.
[94]C. Pandis, N. Brilis, E. Bourithis, D. Tsamakis, H. Ali, S. Krishnamoorthy, A. A. Iliadis, and M. Kompitsas, "Low-temperature hydrogen sensors based on Au nanoclusters and Schottky contacts on ZnO films deposited by pulsed laser deposition on Si and SiO2 substrates," Ieee Sensors Journal, vol. 7, pp. 448-454, Mar-Apr 2007.
[95]A. Eftekhari, "pH sensor based on deposited film of lead oxide on aluminum substrate electrode," Sensors and Actuators B-Chemical, vol. 88, pp. 234-238, Feb 10 2003.
[96]R. M. Cohen, R. J. Huber, J. Janata, R. W. Ure, and S. D. Moss, "Study of insulator materials used in ISFET gates," Thin Solid Films, vol. 53, pp. 169-173, 1978 1978.
[97]D. E. Williams, "Semiconducting oxides as gas-sensitive resistors," Sensors and Actuators B-Chemical, vol. 57, pp. 1-16, Sep 7 1999.
[98]J. C. Chen, J. C. Chou, T. P. Sun, and S. K. Hsiung, "Portable urea biosensor based on the extended-gate field effect transistor," Sensors and Actuators B-Chemical, vol. 91, pp. 180-186, Jun 1 2003.
[99]L. T. Yin, J. C. Chou, W. Y. Chung, T. P. Sun, and S. K. Hsiung, "Study of indium tin oxide thin film for separative extended gate ISFET," Materials Chemistry and Physics, vol. 70, pp. 12-16, Apr 2 2001.
[100]J. L. Deng, "Control-problems of grey systems," Systems & Control Letters, vol. 1, pp. 288-294, 1982.
[101]B. Sohlberg, "Hybrid grey box modelling of a pickling process," Control Engineering Practice, vol. 13, pp. 1093-1102, Sep 2005.
[102]P. Salchner, G. Lubec, and N. Singewald, "Decreased social interaction in aged rats may not reflect changes in anxiety-related behaviour," Behavioural Brain Research, vol. 151, pp. 1-8, May 2004.
[103]C. H. Hsieh and H. C. Chen, "Grey polynomial model," Journal of Grey System, vol. 19, pp. 203-208, 2007.
[104]J. C. Chou, J. L. Chiang, and C. L. Wu, "pH and procaine sensing characteristics of extended-gate field-effect transistor based on indium tin oxide glass," Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers, vol. 44, pp. 4838-4842, Jul 2005.