本研究利用P3HT:PCBM作為太陽能電池主動層，於主動層與陰極金屬Al之間添加一層具有不同能隙寬度之界面層（LiF, Al2O3, TiO2），以了解界面層對於太陽能電池光伏打參數的變化。實驗中在主動層旋轉塗佈完後，利用電子束蒸鍍機蒸鍍Al2O3或TiO2，或熱蒸鍍機蒸鍍LiF作為不同的界面層，再以熱蒸鍍機蒸鍍Al作為太陽能電池陰極金屬，探討P3HT:PCBM系統太陽能電池在主動層與陰極金屬之間添加界面層與否，以及界面層材料對於太陽能電池短路電流、開路電壓、填充因子以及光電轉換效率的影響。另外將添加不同界面層於PFDBC:PCBM系統太陽能電池主動層與陰極金屬之間，在蒸鍍完陰極金屬Al後，將太陽能電池經過熱退火程序，研究太陽能電池添加不同界面層的熱穩定性。
　　實驗中將利用X光光電子能量分析儀對不同界面層做成分以及化學鍵結的分析，並且釐清添加界面層是否會和高分子主動層或是陰極金屬Al產生化學反應；使用原子力顯微鏡針對所添加的界面層表面型態做分析，了解添加不同厚度的界面層對於表面粗糙度的變化；以及利用太陽能模擬器搭配雙極性電源電表量測太陽能電池的光伏打參數，包括：短路電流、開路電壓、填充因子以及光電轉換效率。
　　由實驗結果發現，添加三種界面層（LiF, Al2O3, TiO2）於P3HT:PCBM主動層與陰極金屬Al之間，均不會和主動層或是陰極金屬發生反應；而界面層表面粗糙度的變化極小，不足以影響太陽能電池的光電轉換效率；而光電轉換效率基本上與界面層能隙寬度呈現正相關，添加LiF在P3HT:PCBM系統太陽能電池可以得到最佳的光電轉換效率3.89%，判斷是因為LiF的價帶位置遠低於真空能階（Evac-Ev = 14.1eV），造成其阻擋電洞穿隧能力較佳，避免電子電洞對於Al陰極產生複合，故收集到的光電流較多（短路電流較大），進而增加太陽能電池的光電轉換效率。
　　在添加不同界面層對於太陽能電池的熱穩定性研究則發現，雖然添加LiF可以得到較佳的光電轉換效率，但是當太陽能電池經過10分鐘140℃的熱退火後，無論太陽能電池是否添加界面層，其光電轉換效率均下降，其中只有添加Al2O3的太陽能電池，光電轉換效率損失較少，代表添加Al2O3的太陽能電池熱穩定性較佳。

Materials of different energy band gaps (LiF, Al2O3, TiO2) are investigated as the interlayer between active layer and cathode in P3HT:PCBM organic solar cells. In this study, Al2O3 and TiO2 interlayers were evaporated by E-beam evaporator and LiF interlayers was evaporated by thermo evaporator. By measuring the open circuit voltage, short circuit current, fill factor and power conversion efficiency, we can establish the influence of interlayer on the performance of organic solar cells. In addition, LiF and Al2O3 interlayers are applied to the PFDBC:PCBM solar cell to study the effect of inserting interlayer on the thermo stability of organic solar cells.
The composition and chemical bonding state of the interlayers are analyzed by X-ray photoelectron spectroscopy (XPS). In addition, XPS may examine the possible chemical reaction between interlayer and active layer or cathode. Atomic force microscopy (AFM) is utilized to examine the morphology and roughness of different interlayers. Solar simulator and multi-channel I-V test unit (Keithley 2400) are employed for the measurement of open circuit voltage, short circuit current, fill factor and power conversion efficiency.
XPS data reveal that there is no chemical reaction between interlayer and active layer or cathode. AFM data clearly show that there is no directly relation between root-mean-square roughness and solar cell power conversion efficiency. The power conversion efficiency is generally in proportion to the width of band gap of the interlayer. With LiF interlayer, the power conversion efficiency of P3HT:PCBM solar cell up reaches 3.89% under AM1.5 100mW/cm2 sun light. Because of the wide band gap of LiF (Eg = 14eV), it has a very low valence band (Evac-Ev = 14.1eV). This makes LiF become a very good hole blocking layer. Since Al2O3 has a similar conduction band energy level as that of LiF but higher valence band energy level than that of LiF, organic solar cells with Al2O3 interlayer can achieve only 2.57% of power conversion efficiency.
In PFDBC:PCBM solar cells, the power conversion efficiency of all cells, with or without interlayers, decrease after post-cathode annealing. Despite that inserting LiF interlayer can achieve the highest power conversion efficiency , the power conversion efficiency drops drastically after post-cathode annealing. In contrast, the solar cell with Al2O3 interlayer has a very good thermal stability upon post-cathode thermal annealing.

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沈輝、曾祖勤，太陽能光伏發電技術（化學工業，北京市）
經濟部能源局之中華民國台灣地區能源簡介無障礙網頁http://web2.moeaboe.gov.tw/ecw/About/energy%20situation/main/index.html
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