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Doublet rotational energy transfer of the SH (X (2)Pi, v ''=0) state by collisions with Ar
No full textFine structure-resolved rotational energy transfer of SH (A(2)Sigma(+), v '=0) state by collisions with Ar
No full textMolecular elimination of methyl formate in photolysis at 234 nm: roaming vs. transition state-type mechanism
No full textFine Structure and Λ Splitting – Resolved Rotational Energy Transfer of SH (X2Π, v〃=0 and A2Σ+, v′=0) by Collisions with Ar
No full textSH自由基在大氣、環境、生物體甚至是天文學上都有其重要性。 儘管相關的氣態化學反應動力學(Chemical reaction kinetic)已經有不少的文獻報導, 但是在微觀的動態學(dynamic)方面研究卻鮮少人提及。 特別是SH自由基經非彈性碰撞(inelastic collision)導致的內能能量轉移的領域尚未見到相關的報導。研究SH自由基的內能能量轉移行為理當是對了解相關化學反應動態學有相當的助益. 本論文針對SH自由基(A2Σ+, v′=0 & X2Π, v〃=0)與氬氣(Ar)碰撞誘導轉動能量轉移(rotational energy transfer)過程做實驗與理論兩方面的探討。實驗上觀測到的能量轉移現象可以用量子碰撞計算的結果來佐證。我們應用雷射誘導螢光法(Laser induced fluorescence, LIF)的技術,取得螢光激發(excitation)與放光(emission)光譜可觀察出基態(X2Π, v〃=0)與激發態(A2Σ+, v′=0)精細結構(fine structure)能階的相對數量分佈，進而分析出轉動能量轉移行為。 將SH(A2Σ+, v′=0)與的實驗結果輔以動力學模型可以擬合出SH激發態精細結構能態(fine structure state)的態至態(state to state)能量轉移速率常數。理論方面，使用量子散射理論搭配前人以ab initio方法求得之SH-Ar位能面，我們能計算出轉動能量轉移之碰撞截面與速率常數並與實驗值核對。儘管無法從實驗上量測出SH(X2Π, v〃=0)的態至態速率常數， 我們依然能從時間解析的雷射誘導螢光光譜圖中觀測轉動能量轉移的行為，並且與由速率常數理論值模擬出的轉動分佈比較，檢驗理論數據與實驗值的相符程度。從速率常數的傾向與趨勢所歸納出的一系列碰撞傾向規則(propensity rules)能從微觀的碰撞動態學角度對其行為提出合理解釋。特別是SH(A2Σ+, v′=0)精細結構碰撞傾向與SH(X2Π, v〃=0)Λ分裂態的碰撞傾向可分別由角動量向量模型以及位能面之干涉效應(interference effect of interaction potential)的觀點來說明。 全篇論文可視為首次對SH自由基的轉動能量轉移行為做完整的、有系統的探討。Rotational energy transfer (RET) among the SH (A2Σ+, v′=0) and (X2Π, v〃=0) ro-vibrational levels by collisions with Ar has been studied in both theoretical and experimental manners. The SH (A2Σ+) state is probed using a laser-induced dispersed fluorescence technique, following photodissociation of H2S at 248 nm. The Ar pressure is adjusted appropriately to allow for significant observation of RET process in single collision condition. The spin-resolved rate constants are then evaluated with the aid of a kinetic model: Firstly, a set of rate constants is determined from experimental data by assuming single collision approximation. Then such initial guess values are substituted into rate equation and an iterative process is performed in order to obtain converged rate constants which incorporated the multi collision effect. The theoretical counterparts of both SH (A2Σ+ v′=0) and (X2Π v〃=0) can be calculated by using quantum scattering method with newly fitted potential energy functions based on ab initio potential energy surfaces. Although the Λ doublet resolved rate constants of SH (X2Π, v〃=0) are merely determined via theoretical calculation, experimental time resolved rotational populations are measured via laser induced fluorescence (LIF) technique and compared with simulation in order to examine the reliability of theoretical data. For the SH (A2Σ+ v=0) case, the experimental and theoretical kinetic results are essentially consistent in the trend of N (spinless angular momentum quantum number) and ΔN dependence. The principle of microscopic reversibility is also examined for both experimental and theoretical kinetic data, showing that translational energies of the RET collisions are close to thermal equilibrium at room temperature. Fine structure conserving propensity is found in the fine structure resolved rate constants. Such propensity can be rationalized according to angular momentum vector model. For the SH (X2Π, v〃=0) results, RET rate constants of Λ doublet levels are determined theoretically. In order to examine the reliability of theoretical data, experimental time resolved SH (X2Π, v〃=0) rotational populations are measured via LIF technique and compared with theoretical simulation. Several propensity rules are found in the Λ resolved rate constants, either favor the final level with certain reflection symmetry or tend to conserve the parity. Explanations are given for these propensity rules, basing on both the high collision energy limit and the interference effect in interaction potentials
A Theoretical model for Conjugated Polymer Solar Cells
No full text石油一直是人類所依賴的主要能源，但近一兩年來石油的價格不斷攀升，大幅度的價格變化甚至直接衝擊了全球經濟和民生物價，因此找尋可替代能源的議題越來越顯得重要，而太陽能電池是眾多替代能源中最具有潛力的，因為太陽能電池可直接從太陽捕獲能量並且在使用上無汙染。市面上太陽能電池的種類很多，其中導電高分子太陽能電池是目前最具前瞻性的太陽能電池類型，其發展的時間也是所有種類中最晚的，但導電高分子太陽能電池因為具許多的優點所以特別受人注目，尤其是可攜帶性及易於製造等優點，但是低效率的問題卻一直是導電高分子太陽能電池所面臨的一大挑戰，因此若能有數學模型去描述電池內部的機制，那麼對於導電高分子太陽能電池的研究會是相當有幫助的。 在本論文研究中，我們將建立一個導電高分子太陽能電池的數學模型，利用數值解的方法去求解卜瓦松方程式和質量守恆關係式，藉此將模擬計算出導電高分子太陽能電池的放電表現，而模型中的物理參數分佈將可以幫助我們分析各個操作點時的狀況，以了解整體機制。論文中我們將使用兩組實驗數據去比對模型的計算結果，比對之後發現此模型的計算結果和實驗點之間都有不錯的結果，並進一步證明此模型具有一定的參考價值，之後我們將改變材料的物性參數，希望能找出影響電池效率的關鍵因素，相信這些資訊都能有助於找出解決低效率問題的方法，進而達到改善太陽能電池的效率值。The fossil oil has been the primary source energy which the modern human society relies on. Recently, the price of crude oil increase dramatically and it impacts the global economy and the livelihood of the people. To solve this problem, it is necessary to develop other inexpensive energy sources to reduce our dependence on oil. Therefore searching for alternative energies is an important issue. The solar cell has great potential among the numerous alternative energy sources, because it directly captures the solar energy from the sun and does not release chemical pollutant during operation. There are many types of solar cells on the market. The conjugated polymer solar cell is a new generation of solar cell at the present. Although its development started very recently, it has attracted a significant amount of attention because of a lot of advantages, especially its low cost and the ease of fabrication. However, the low efficiency (currently about 6%) problem has been a big challenge for the conjugated polymer solar cell and makes it impossible for commercialization. If we can have a mathematical model to describe the internal mechanism inside the cell, it would be helpful to find the optimal design of the conjugated polymer solar cells. In this thesis, we developed a numerical model for polymer/fullerene bulk heterojunction solar cell. Using this model, we can simulate the electric performance of solar cell and the result is consistent with experimental current-voltage curve. On the other hand, we can analyze the distribution of physical properties to better understand the distribution and transport of electrons and holes inside the solar cell. Based on the good agreement with experiments, the prediction of solar cell''s efficiency can be calculated by changing the material''s parameters in the model. Our analysis suggests that the key factors for the efficiency are orbital energies of materials. Finally, the mathematic model can also offer an efficiency table for the new material development to solve the low efficiency problem.目錄試委員會審定書 I謝 II文摘要 IVbstract V索引 VIII索引 X. 緒論 1.1 研究背景 1.2 太陽能源介紹 1.3 太陽能電池的種類和簡介 2.4 導電高分子太陽能電池 6. 混摻異質接面型太陽能電池 8.1 混摻異質接面型太陽能電池介紹和工作原理 8.2 太陽能電池的電流-電壓特徵曲線圖介紹 10.3 發展數學模型的目的 12. 數值解模型的建立 13.1 數學模型的原理與方程式 13.1.1 半導體元件基本統御方程式 14.1.2 自由載子的淨產生速率 16.1.3 Braun’s model 19.1.4 統御方程式整理 21.2 電子-電洞對的產生速率 22.3 邊界條件 24.3.1 電位的邊界條件 24.3.2 金屬和有機界面的電荷注入 25.3.3 電流密度的邊界方程式整理 28. 模型的數值方法 31.1 數值方法解邊界值問題 31.1.1 有限差分法和統御方程式的離散化 31.1.2 牛頓法 34.2 Scharfetter-Gummel Approximation 離散化 36.3 離散化統御方程式整理 39.4 模型求解流程 40.5 模型參數 42. 結果與討論 46.1 電流-電壓特徵曲線圖 46.2 電池內部物理參數分佈 49.3 不同照光強度下的電流-電壓特徵曲線圖 55.4 開環電壓和短路電流預測 59.5 電子和電洞的遷移率對於放電效率的影響 61.6 電極工作函數對於放電效率的影響 65.7 高分子材料的能階對於放電效率的影響 68. 結論 70考文獻 72錄 7
Photodissociation of gaseous propionyl chloride at 248 nm by time-resolved Fourier-transform infrared spectroscopy
No full textOrientation dependence in the four-atom reaction of OH plus HBr using the single-state oriented OH radical beam
No full textOrientation dependence for Br formation in the reaction of oriented OH radical with HBr molecule
No full textI(2) molecular elimination in single-photon dissociation of CH(2)I(2) at 248 nm by using cavity ring-down absorption spectroscopy
No full textProbing the Ignored Elimination Channel of Br-2 in the 248 nm Photodissociation of 1,1-Dibromoethylene by Cavity Ring-Down Absorption Spectroscopy
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