The Fabrication of Poly(3-octylthiophene) / Carbon Nanotubes Nano-Composite and Photovoltaic Device Application

本研究主要是探討聚三辛基塞吩和奈米碳管的複合材料製作及光電性質量測。為了使元件工程進行得更順利，必須從碳管及高分子的單一材料控制和鑑定開始。 直接成長碳管方面以密度控制和長度控制為主題，以成長直立陣列碳管為目標。高分子的基礎鑑定則以旋鍍轉速和成膜品質的關係為第一部份；第二部分則是探討高分子因退火效應結晶化的光學及電學研究。 第三部分則是製作複合材料及電性量測。實驗結果方面，直接成長碳管於基板上的策略遭遇重大的挫折，並瞭解到將聚三辛基塞吩填充入奈米結構中是一難度極高的工程問題。解決界面工程的策略是採用表面改質技術。除了電性量測外、並使用時間解析光譜測定，發現到載子存在時間隨著碳管密度的增加有減少的趨勢。In this thesis, the engineering part of the solar cell of spin coating, annealing and composite fabrication were studied. In theory, the direct growth aligned carbon nanotubes and P3OT can be fabricated into the composite and have high solar energy conversion efficiency, the direct growth carbon nanotubes can serve as conducting channel to extract electron out of the composite. However, this kind of structure’s fabrication shows high difficulty in engineering aspect. The poor coverage of the P3OT on carbon nanotubes indicates that there exists interface problem between the carbon nanotubes and P3OT. First, we have to make sure what the important parameter determines the polymer solar cell’s efficiency. After investigating the spin coating rate influence, we found that the spin rate only affect the P3OT’s thickness. Second, we study the annealing effect on the P3OT’s structure. The amorphous conducting polymer needs to become crystallized that polymer’s application on electronics can become possible. We characterize the structure by absorption spectrum, photoluminescence spectrum, X-ray diffraction. And found the ordering’s evidence in the spectrum: Absorption spectrum’s peak splitting, PL spectrum’s Huang-Rhys Factor decreases as annealing temperature increases, this phenomenon shows that effective conjugation length of the polymer chain increases. X-ray’s results shows that the d-spacing of the polymer decreases, shows that the packing of the structure become denser. Finally, we study the P3OT / Direct Growth Aligned Carbon Nanotubes composite fabrication. Applying length controlled and density controlled carbon nanotubes on this structure and using surface modification technique to increase the hydrophilicity of the carbon nanotbes surface in order to overcome the interface coverage problem. The electric properties of the composite has been characterized.摘要 I ABSTRACT II ACKNOWLEDGEMENT IV 目錄 VI 表目錄 VIII 圖目錄 IX CHAPTER 1 INTRODUCTION 1 1.1 研究目的 1 1.2 文獻回顧 3 1.2.1 緒論 3 1.3 研究動機 7 CHAPTER 2 FUNDAMENTAL OF PHOTOVOLTAIC DEVICE 10 2.1導論 10 2.2 材料受光激發後的光伏特性 11 2.3光伏元件性能與特性 13 2.3.1量子效率(Quantum Efficiency) 17 2.3.2能量轉換效率(Power Efficiency) 18 2.3.3頻譜響應(Spectral Response) 20 CHAPTER 3 SYNTHESIS AND CHARACTERIZATION OF ALIGNED CARBON NANOTUBES 24 3.1緒論 24 3.1.1研究背景 24 3.1.2奈米碳管的結構(Structure of carbon nanotubes) 25 3.1.3奈米碳管合成的方法(The methods of synthesizing carbon nanotube) 29 3.2奈米碳管在光伏元件上的應用 32 3.3奈米碳管的成長控制文獻探討 34 3.3.1奈米碳管的密度控制 34 3.3.2奈米碳管的長度控制 36 3.3.3奈米碳管的半徑控制 36 3.4實驗流程 36 3.4.1實驗流程與設計 36 3.4.2實驗儀器簡介 37 3.5結果與討論(RESULTS AND DISCUSSION) 42 3.5.1不同鐵-矽比率在鈦/矽基板上成長奈米碳管的影響 42 3.5.2短時間成長奈米碳管對長度的影響 46 3.5.3短時間成長密度控制碳管在鈦/矽基板上 48 3.5.4短時間成長密度控制碳管在矽基板上 52 3.5.5奈米碳管的X光結晶繞射鑑定 54 CHAPTER 4 GENERAL PROPERTIES OF CONDUCTING POLYMER 56 4.1導電高分子 56 4.2高分子結構的特點 58 4.3 分子材料受光激發之物理性質 59 4.4 載子在材料內的傳輸行為 60 4.5聚三辛基塞吩的基本性質 61 4.6純聚三辛基塞吩單層光伏元件製作及原理 63 4.6.1元件結構設計(圖4-6) 63 4.6.2實驗儀器簡介 64 4.6.3實驗步驟及規劃 66 4.7實驗結果 66 4.7.1旋鍍轉速對高分子膜產生的影響 66 4.7.2退火溫度對聚三辛基塞吩的研究 79 4.8結果與討論 87 CHAPTER 5 OPTICAL PROPERTIES AND ELECTRICAL PROPERTIES OF POLY (3-OCTYLTHIOPHENE)/CARBON NANOTUBES HYBRID SYSTEM 96 5.1有機高分子/半導體混參系統簡介 96 5.1.1混漿塗佈元件策略 96 5.1.2直接成長元件策略 98 5.2聚三辛基塞吩/直接成長多壁奈米碳管系統之研究 100 5.2.1聚三辛基塞吩/直接成長多壁奈米碳管元件工程 100 5.2.2聚三辛基塞吩/直接成長奈米碳管光性的探討 103 5.2.3聚三辛基塞吩/直接成長奈米碳管元件電性的探討 106 CHAPTER 6 CONCLUSION 109 REFERENCES 11