臺灣博碩士論文加值系統

我們利用LB技術（Langmuir-Blodgett Technique）製備染料敏化太陽電池（Dye-Sensitized Solar Cells，DSSC）之TiO2粒子薄膜電極，研究TiO2薄膜表面粗糙度（surface roughness）對染料敏化太陽電池的導電影響與TiO2粒子薄膜表面特性。由實驗結果可得知，沉積20nm粒徑大小的TiO2粒子在基板上，來改善FTO玻璃基板的表面粗糙度，使LB單層膜與TiO2粒子層有更好的接觸，來提高染料敏化太陽電池的總效率由1.7%增加至2.5%，提升了47%。
藉由成長不同粒徑、條件的TiO2粒子薄膜，量測其薄膜表面形貌之改變與接觸角的變化。從原子力顯微鏡（Atomic Force Microscope，AFM）圖形可觀測，藉由沉積5nm、60nm粒徑大小的TiO2粒子，得到較高的薄膜表面粗糙度，由於較高粗糙度LB膜與TiO2粒子層無法形成較好的接觸，使總效率下降。

We study the impact of surface roughness of TiO2 thin films on dye-sensitized solar cells and the characteristic of surface of TiO2 thin films. Langmuir-Blodgett (LB) technology was utilized to prepare TiO2 thin film electrodes of the dye-sensitized solar cells.The result clearly demonstrates that the presence of the LB layer significantly improved the contact between the FTO and the main TiO2 layer by particle size of 20nm deposited TiO2 particle. As a result, the conversion efficiency was improved by 47.0% from 1.7% to 2.5% due to the introduction of the interfacial P25 LB layer.
From atomic force microscopy (AFM) images it was found that the particle size of 5nm and 60nm deposited TiO2 particle have high surface roughness and LB film with high surface roughness of TiO2 particles cannot form a good contact, bringing the total decline in their efficiency.

目錄
摘要..........................................................................I
Abstract....................................................................II
謝誌........................................................................III
目錄.........................................................................IV
圖表目錄....................................................................VII
第一章 緒論....................................................................1
1-1前言.......................................................................1
1-2 太陽能電池.................................................................2
1-3 研究動機..................................................................3
第二章 實驗原理與儀器架構........................................................4
2-1 The Langmuir-Blodgett Technique...........................................4
2-1.1 簡史....................................................................4
2-1.2 Langmuir 薄膜於氣液介面的散佈.............................................5
2-1.3 壓膜過程之π-A等溫線......................................................7
2-1.4 Langmuir-Blodgett薄膜的轉移............................................10
2-2 染料敏化太陽能電池（DSSC）................................................11
2-3 原子力顯微鏡(AFM)........................................................13
2-4 接觸角基本理論...........................................................15
2-5 表面粗糙度...............................................................18
第三章 實驗流程...............................................................20
3-1 TiO2 粒子膠體溶液的製備...................................................20
3-1.1 靜電吸附法.............................................................20
3-1.2 改質TiO2粒子表面.......................................................20
3-2 基板準備................................................................21
3-3 Langmuir-Blodgett單層膜製備流程.........................................21
3-3.1 水槽的潔淨............................................................21
3-3.2 單層薄膜的轉移........................................................21
3-4 接觸角量測..............................................................23
3-5 太陽能電池組裝...........................................................23
第四章 結果與討論.............................................................25
4-1 基板改質.................................................................25
4-2 TiO2薄膜表面粗糙度與接觸角變化.............................................26
4-2.1 LB製膜的表面壓力等溫線..................................................26
4-2.2 表面形貌與接觸角變化.....................................................31
4-2.3超疏水SiO2粒子薄膜.......................................................44
4-3 TiO2薄膜表面粗糙度與電池效率...............................................49
4-3.1 LB製膜的表面壓力等溫線...................................................49
4-3.2 薄膜電極之表面形貌與電池效率...........................................51
4-3.3光電轉換效率（Incident Photo to Current conversion Efficiency，IPCE）.....64
4-3.4 電化學阻抗頻譜（Electrochemical Impedance Spectroscopy，EIS）............65
第五章 結論...................................................................66
參考文獻......................................................................67


 
圖表目錄
（圖2-1）Langmuir 單分子層的形成................................................6
（圖2-2）氣液界面上單分子層表面壓-每分子佔據面積的等溫線............................8
（圖2-3）LB 膜的沉積…........................................................10
（圖2-4）染料敏化太陽電池結構與發電機制簡圖......................................12
（圖2-5）AFM 工作原理.........................................................14
（圖2-6）Young’s Equation模型................................................15
（圖2-7）Wenzel’s Model......................................................16
（圖2-8）Cassie’s Model......................................................17
（圖2-9）中心線平均粗糙度......................................................18
（圖2-10）十點平均粗糙度......................................................19
（圖2-11）最大表面粗糙度......................................................19
（圖3-1）Langmuir-Blodgett 薄膜製備儀器MODEL 312D 架構.........................22
（圖3-2）電池組裝示意圖........................................................24
（圖3-3）測試儀器裝置示意圖....................................................24
（圖4-1）改質前後接觸角變化....................................................25
（圖4-2）散佈ODA於液面（純水）之表面壓力等溫線...................................27
（圖4-3）利用靜電吸附法製備TiO2 LB薄膜.........................................27
（圖4-4）利用靜電吸附法製備TiO2 LB薄膜，pH=2.00................................28
（圖4-5）利用靜電吸附法製備TiO2 LB薄膜，pH=3.01................................28
（圖4-6）利用靜電吸附法製備TiO2 LB薄膜，pH=8.00................................29
（圖4-7）改變不同TiO2膠體溶液pH值拉膜..........................................29
（圖4-8）改質TiO2粒子製備TiO2 LB薄膜，P=15 mN/m...............................30
（圖4-9）改質TiO2粒子製備TiO2 LB薄膜，P=30 mN/m...............................30
（圖4-10）改質粒子P=15 mN/m TiO2粒子薄膜......................................33
（圖4-11）改質粒子P=15 mN/m TiO2粒子薄膜之3D圖.................................34
（圖4-12）改質粒子P=30 mN/m TiO2粒子薄膜.......................................35
（圖4-13）改質粒子P=30 mN/m TiO2粒子薄膜之3D圖..................................36
（圖4-14）TiO2粒子薄膜之表面形貌pH=2.00.........................................37
（圖4-15）TiO2粒子薄膜之表面形貌pH=2.00之3D圖...................................38
（圖4-16）TiO2粒子薄膜之表面形貌pH=3.01........................................39
（圖4-17）TiO2粒子薄膜之表面形貌pH=3.01之3D圖...................................40
（圖4-18）TiO2粒子薄膜之表面形貌pH=8.00.........................................41
（圖4-19）TiO2粒子薄膜之表面形貌pH=8.00之3D圖...................................42
（圖4-20）表面粗糙度對應接觸角量測值............................................43
（表4-1）不同條件下，表面粗糙度對應接觸角量測值..................................43
（圖4-21）蓮花表面結構........................................................44
（圖4-22）超疏水SiO2粒子薄膜，接觸角θ=156.71°..................................45
（圖4-23）超疏水SiO2粒子薄膜之表面形貌.........................................46
（圖4-24）超疏水SiO2粒子薄膜之表面形貌（部份放大）...............................47
（圖4-25）超疏水SiO2粒子薄膜之表面形貌之3D圖....................................48
（圖4-26）靜電吸附法製備TiO2 LB薄膜電極：5 nm...................................50
（圖4-27）靜電吸附法製備TiO2 LB薄膜電極：60 nm..................................50
（圖4-28）UV穿透光譜..........................................................52
（圖4-29）電池示意圖...........................................................52
（圖4-30）TiO2 LB薄膜電極：5 nm之表面形貌......................................54
（圖4-31）TiO2 LB薄膜電極：5 nm之表面形貌之3D圖.................................55
（圖4-32）TiO2 LB薄膜電極：60 nm之表面形貌.....................................56
（圖4-33）TiO2 LB薄膜電極：60 nm之表面形貌之3D圖................................57
（圖4-34）FTO玻璃/ LB film/ T100 film，I-V曲線................................58
（圖4-35）FTO玻璃/ LB film/ ITO導電層/ T0 film(P25)，I-V曲線...................58
（圖4-36）TiO2 LB薄膜電極：20 nm之表面形貌......................................60
（圖4-37）TiO2 LB薄膜電極：20 nm之表面形貌之3D圖................................61
（圖4-38）TiO2 LB薄膜電極：20 nm薄膜厚度之表面形貌..............................62
（圖4-39）FTO玻璃/ LB film/ T0 film(P25)，I-V曲線.............................63
（表4-2）Isc、Voc、FF、Eff....................................................63
（圖4-40）IPCE spectra for the DSSCs with and without LB film................64
（圖4-41）電化學阻抗頻譜.......................................................65

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