在缺陷工程領域中，透過靜電紡絲及退火調控溫度(400˚C、600˚C)及氧氣濃度(20 %、100 %)的製程差異製作出不同氧空缺濃度的多晶二氧化錫奈米纖維(Poly crystalline tin oxide nanofibers, poly-SnO2 NFs)，並且研究其感測效應。基於製程控制可以改變材料的氧空缺濃度，進而影響缺陷能階分布。此外，晶體大小、結晶程度及介面/表面缺陷對光與氣體感測皆有強烈影響。

為了證實氧空缺濃度確實會影響感測效應，並且不同缺陷能階會吸收不同能量的光，所以本研究利用多波段LED光(365 nm、465 nm)激發不同缺陷能階中的束縛電子形成光電感測器。另外，富含介面/表面氧空缺濃度的poly-SnO2 NFs能有效提升有毒氣體感測(NO(g))能力，同時也具有調控水氣感測效應。因此透過相異氧空缺濃度所產生不同缺陷能階來進一步探討不同濕度的量測環境對於poly-SnO2 NFs感測元件電流值的變化量。基於以上研究，可以透過控制一系列參數來形成多晶二氧化錫奈米纖維，以實現光和氣體等各種感測應用。

For defect engineering research, oxygen vacancies (Vo) structure of polycrystalline SnO2 nanofibers (poly-SnO2 NFs) can be fabricated by using electrospinning and thermal annealing process, which is different annealing temperature ( 400˚C, 600˚C ) and gas concentration ( 20 %, 100 % ) to study the sensing effect. Based on tuning the fabrication process, the different defect energy levels can be formed due to the various Vo structures. In addition, the grain size and the amount of interface/surface Vo have strong infection to affect the photo and gas detection.
To confirm that the Vo structure affect the sensing ability, and different defect energy levels can absorb different energy. In this work, the different defect energy levels can absorb multi-wavelength (365 nm, and 465 nm ) LED light to excite the trapping electron on defect levels to form photon electric current sensor. In addition, the rich surface/interface Vo of poly-SnO2 NFs also can be powerful units to enhance the toxic gas (NO(g)) and tune the water vapor detect ability. Thus, the defect energy levels effect can be further investigated by changing the relative humidity to see the difference of current performance of poly-SnO2 NFs. Based on this research, the well detection poly-SnO2 NFs can be formed through a series parameter controlling to achieve various application, such as photo and gas sensing.

目錄
第一章　簡介...1
1.1　動機...1
1.2 奈米材料的演變...2
1.2.1　一維奈米結構...2
1.3　一維半導體奈米結構應用...3
1.3.1　光電效應的應用...3
1.3.2　表面奈米結構氣體感測器...4
1.4　二氧化錫晶體結構(Rutile)...4
1.5　晶體成長...5
1.5.1　成核...6
1.5.2生長...7
1.6　材料之晶體結構...7
1.6.1　單晶結構...8
1.6.2　多晶結構...8
1.6.3　非晶結構...8
1.7　金屬-半導體接觸元件...9
1.7.1　歐姆接觸...10
1.7.2　蕭特基接觸...11
第二章　元件製作及儀器介紹...13
2.1　材料製程與元件製備...13
2.1.1　多晶氧化金屬 ( SnO2 ) 奈米線的製程...13
2.1.2　多晶SnO2奈米纖維元件製作...14
2.1.3　光感測實驗流程...14
2.2　儀器介紹...15
2.2.1　奈米靜電紡絲機...15
2.2.2　管型高溫爐...16
2.2.3　電性量測系統...17
2.2.4　掃描式電子顯微鏡(SEM)...17
2.2.5　MIPAR圖像數據分析軟體...18
2.2.7　穿透式電子顯微鏡（TEM）...19
2.2.8　X光光電子能譜術(XPS)...20
第三章 結果與討論...21
3.1　不同退火條件的Poly-SnO2 NFs...21
3.1.1　Poly-SnO2 NFs表面結構與特性分析...21
3.1.1.1　SEM分析...21
3.1.1.2　EDS分析...23
3.1.1.3　TEM分析...24
3.1.2　不同製程材料之氧空缺分布分析...25
3.1.2.2　XPS分析...25
3.1.3　Poly-SnO2 NFs光感測器之光電性質量測...27
3.1.3.1　金屬-半導體-金屬結構元件...27
3.1.3.2　不同氧空缺濃度之Poly-SnO2 NFs電性...28
3.1.3.3　不同氧空缺濃度之poly-SnO2 NFs光學特性...30
3.2　相異氧空缺濃度Poly-SnO2 NFs之光輔助一氧化氮氣體感測的特性33
3.2.1　電性與物理機制...33
3.2.2　不同氧空缺濃度Poly-SnO2 NFs之光輔助NO氣體感測性質...34
3.2　濕度對Poly-SnO2 NFs光感測器影響...36
3.2.1　濕度對Poly-SnO2 NFs光感測器之光電特性量測...36
3.2.1.1　電性與物理機制...36
3.2.1.2　相異氧空缺濃度之Poly-SnO2 NFs的溼度輔助光感測性質...37
第四章　結論...40
第五章　未來展望...41
5.1　濕度變化之有毒氣體感測...41
5.2　不同氧空缺濃度之多晶奈米纖維之異質接面元件...41
參考文獻...42

圖目錄
圖1.1、(a)光電效應(b)半導體光激發示意圖。...3
圖1.2、n型金屬氧化物半導體與氧化性氣體表面(a)反應前(b)反應後示意圖。...4
圖1.3、SnO2之四方金紅石相結構圖[25]。...5
圖1.4、成核自由能示意圖[31]。...7
圖1.5、單晶結構排列示意圖。...8
圖1.6、多晶結構排列示意圖。...8
圖1.7、非晶結構排列示意圖。...9
圖1.8、金屬與半導體材料能帶示意圖。...10
圖1.9、(a)歐姆接觸元件之電壓-電流特性曲線。(b)金屬-半導體材料形成接面前後能帶圖。...11
圖1.10、(a)蕭特基接觸元件之電壓-電流特性曲線。(b)金屬-半導體材料形成接面前後能帶圖。...12
圖1.11、(a)歐姆接觸元件 (b)蕭特基接觸元件之氣體感測I-t曲線[38]。...12
圖2.1、多晶氧化金屬奈米線製程流程圖。...13
圖2.2、SnO2奈米纖維之元件製作流程。...14
圖2.3、(a)自製光盤。(b)不同波長的分布圖。...15
圖2.4、Falco Enterprise CO. Ltd. FES-CO2S型靜電紡絲機。...16
圖2.5、管型高溫爐及溫度控制器。...16
圖2.6、安捷倫B1500A半導體元件分析儀與探針量測系統腔體。...17
圖2.7、Carl Zeiss SIGMA型之熱場發式電子顯微鏡及X光能量散射光譜儀。...18
圖2.8、(a)Poly-SnO2 NFs之SEM圖的定量分析區域。(b)晶粒大小分布量化數據。...19
圖2.9、JEOL Ltd. JEM-2100F型穿透式電子顯微鏡。...20
圖3.1、製程差異所製作出poly-SnO2 NFs之(a)SEM圖。(b)定面積之影像分析圖。(c)粒徑分布。...22
圖3.2、不同退火製程下的poly-SnO2 NFs之(a)EDS光譜全圖。(b)Sn及(c)O元素光譜圖。...23
圖3.3、製程差異製作出的多晶SnO2奈米纖維之(a)低倍率TEM圖(magnitude：40 KX)。(b)高解析TEM圖。(c)選區繞射。...25
圖3.4、四種不同退火條件所得之poly-SnO2 NFs (a) O 1s峰。(b) Sn 3d結合能。...26
圖3.5、相異氧空缺濃度之poly-SnO2 NFs的XPS O 1s線性擬合。...27
圖3.6、金屬-半導體-金屬結構元件(a)施加偏壓(b)施加偏壓下照光之能帶圖。...28
圖3.7、(a)400˚及(b)600˚C退火環境所得poly-SnO2 NFs感測元件於未照光情況下之I-V特性曲線。...29
圖3.8、相異氧空缺濃度之poly-SnO2 NFs感測元件(a)光感測電流-時間特性曲線。(b)於未照光與不同波光照環境之能帶機制圖。...32
圖3.9、Poly-SnO2 NFs感測元件於(a)未照光之有毒氣體(b)照UV光(c)光輔助之有毒氣體感測機制圖[54]。...34
圖3.10、(a)20 % O2之不同溫度與(b)600˚C之不同氧氣濃度退火環境所製出的poly-SnO2 NFs感測元件的電流-時間特性曲線。...35
圖3.11、Poly-SnO2 NFs於(a)未通水氣(b)通入水氣之量測環境的能帶示意圖。...37
圖3.12、(a)20 % O2 @ 400˚C、(b)20 % O2 @ 600˚C及(d)100 % O2 @ 600˚C退火環境製作出的poly-SnO2 NFs在不同濕度氮氣環境光感測的電流變化量。...39

表目錄
表1.1、SnO2之四方金紅石結構數據[26-28]。...5
表3.1、相異氧空缺濃度之poly-SnO2 NFs於不同波段光照環境的電流變化量。...32

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