本論文成功地研製出三種新型的二氧化鈰電阻式氣體感測器，分別為鈀奈米顆粒修飾二氧化鈰薄膜氫氣感測器、鉑奈米顆粒修飾二氧化鈰薄膜氨氣感測器、及金奈米顆粒修飾二氧化鈰薄膜甲醛感測器。
首先，第二章的氫氣感測器結構是由射頻濺鍍形成二氧化鈰薄膜和利用快速熱蒸鍍法將鈀形成奈米顆粒合成，其中，鈀奈米顆粒結構可以有效提高元件的比表面積，使元件對氫氣分子的吸附作用大量提高，進而增強對氫氣的感測特性和表現，在最佳溫度350°C下對1%氫氣具有極高的感測響應為120.2，還有極快的反應時間和脫附時間為5秒和17秒。
接著，第三章的氨氣感測器結構是由射頻濺鍍形成二氧化鈰薄膜和利用快速熱蒸鍍法將鉑形成奈米顆粒合成，其中，鉑奈米顆粒結構可以有效提高元件的比表面積，使元件對氨氣分子的吸附作用大量提高，進而增強對氨氣的感測特性和表現，在最佳溫度275°C下對1000 ppm氨氣具有相對高的感測響應為5.8，反應時間為198秒。
最後，第四章的甲醛感測器結構是由射頻濺鍍形成二氧化鈰薄膜和利用快速熱蒸鍍法將金形成奈米顆粒合成，其中，金奈米顆粒結構可以有效提高元件的比表面積，使元件對甲醛分子的吸附作用大量提高，進而增強對甲醛的感測特性和表現，在最佳溫度300°C下對20 ppm甲醛具有相對高的感測響應為2.93，反應時間為102秒。
此外，為了證明金屬奈米顆粒的存在及薄膜成份，使用掃描電子顯微鏡 (SEM)、能量色散X-射線光譜儀 (EDS)、 穿透式電子顯微鏡 (TEM) 及原子力分析顯微鏡 (AFM) 來分析感測器結構、薄膜表面金屬分布和元素成分。

In this thesis, three new chemiresistive cerium oxide (CeO2) gas sensors have been successfully fabricated, which are Pd NP/CeO2-based gas sensor, Pt NP/CeO2-based gas sensor and Au NP/CeO2-based gas sensor, respectively.
First, the structure of the hydrogen gas sensor in Chapter 2 is synthesized with a radio frequency (RF) sputtered cerium oxide (CeO2) thin film and rapid thermal evaporated palladium (Pd) nanoparticles (NPs). Among them, the structure of Pd NPs can effectively improve the surface area/volume (SA/V) ratio of device, thereby substantially enhancing the adsorption effect of hydrogen molecules on the device surface and improving the related sensing performance, containing a high sensing response of 120.2 accompanied by a fast response time of 5 s and recovery time of 17 s under 1% H2/air gas at 350°C.
Then, the structure of the ammonia gas sensor in Chapter 3 is synthesized with a radio frequency (RF) sputtered cerium oxide (CeO2) thin film and rapid thermal evaporated platinum (Pt) nanoparticles (NPs). Among them, the structure of Pt NPs can effectively improve the surface area/volume (SA/V) ratio of device, thereby substantially enhancing the adsorption effect of ammonia molecules on the device surface and improving the related sensing performance, containing a relatively high sensing response of 5.8 accompanied by a relatively fast response time of 198 s under 1000 ppm NH3/air gas at 275°C.
Finally, the structure of the formaldehyde gas sensor in Chapter 4 is synthesized with a radio frequency (RF) sputtered cerium oxide (CeO2) thin film and rapid thermal evaporated gold (Au) nanoparticles (NPs). Among them, the structure of Au NPs can effectively improve the surface area/volume (SA/V) ratio of device, thereby substantially enhancing the adsorption effect of formaldehyde molecules on the device surface and improving the related sensing performance, containing a relatively high sensing response of 2.93 accompanied by a relatively fast response time of 102 s under 20 ppm HCHO/air gas at 300°C.
In addition, to confirm that the metal had formed nanoparticle structure and the composition of thin film. This study will also analyze the device structure, surface morphology and elemental composition of CeO2 based gas sensors with scanning electron microscope (SEM), energy dispersion X-ray spectrometer (EDS), transmission electron microscope (TEM), and atomic force microscope (AFM).

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