本研究以五苯環摻混於有機高分子太陽能電池主動層，藉此改變薄膜形貌以及增進薄膜載子(電洞)的移動率，進而改善有機高分子太陽能電池的轉換效率。於我們實驗中，以P3HT:PCBM:pentacene=1:0.8:0.09之主動層條件有最佳轉換效率，與傳統(P3HT:PCBM=1:0.8)有機高分子太陽能電池相比，其轉換效率由3.28%提升至4.21%。接著以原子力顯微鏡，X光繞射光譜，紫外光-可見光吸收光譜以及空間電荷限制電流法計算載子移動率來探討主動層摻混不同比例之五苯環對於元件特性的影響。此外，利用熱退火處理改善P3HT:PCBM:pentacene=1:0.8:0.1之有機高分子太陽能電池轉換效率，而實驗出，以150℃, 20minutes進行薄膜熱退火處理，P3HT:PCBM:pentacene=1:0.8:0.1之有機高分子太陽能電池得到最佳化，其元件特性為:開路電壓0.67V，短路電流13.80 mA/cm2，填充因子57.2%，轉換效率5.29%。

In this study, pentacene was blended into the active layer to change the morphology and enhance hole mobility of P3HT:PCBM films. Therefore, the conversion efficiency of P3HT:PCBM solar cell was improved. The experimental results showed that the device with P3HT:PCBM:pentacene=1:0.8:0.09 as active layer utilized the best performance. Compared with the conventional polymer solar cells, the conversion efficiency was increased from 3.28% to 4.21%. In order to demonstrate the influences of the device performance with different ratio of pentacene, the AFM measurements, x-ray diffraction (XRD) measurements, the absorption spectrum, and the carrier mobility estimated by the space charge limited current method were used. Moreover, the P3HT:PCBM:pentacene=1:0.8:0.1 solar cell was annealed under different temperature conditions to optimize the best performance. The device showed the best performance with open-circuit voltage (VOC) of 0.67 V, short-circuit current (JSC) of 13.80 mA/cm2, fill factor (F.F) of 57.2%, and conversion efficiency of 5.29% under the thermal annealing at 150℃ for 20 minutes.

[1] R. A. Keer, “Climate change-Scientists tell policymakers we’re all warming the world”, Science, 315, 754 (2007).
[2] C. K. Chiang, C. R. Fincher Jr., Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis, S. C. Gau, and A. G. MacdDiarmid, “Electrical conductivity in doped polyacetylene”, Phys. Rev. Lett., 39, 1098 (1977).
[3] J. M. Nunzi, “Organic photovoltaic materials and devices”, C. R. Phys. 3, 523 (2002).
[4] W. Ma, C. Yang, X. Gong, K. Lee, A. J. Heeger, “Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology”, A. J. Adv. Funct. Mater., 15, 1617 (2005).
[1] J. Nelson, “Organic photovoltaic films ”, Curr. Opin. Solid State Mater. Sci., 6, 87 (2002).
[2] J. J. Dittmer, E. A. Marseglia, and R. H. Friend, “Electron Trapping in Dye/Polymer Blend Photovoltaic Cells”, Adv. Mater., 17, 1270 (2002).
[3] J. Y. Kim and A. J. Bard, “Organic donor/acceptor heterojunction photovoltaic devices based on zinc phthalocyanine and a liquid crystalline perylene diimide”, Chem. Phys. Lett., 383, 11 (2004).
[4] V. D. Mihailetchi, P. W. M. Blom, J. C. Hummelen, and M. T. Rispens, “Cathode dependence of the open-circuit voltage of polymer:fullerene bulk heterojunction solar cells”, J. Appl, Phys, 94, 6849 (2003).
[5] C. J. Brabec, A. Cravino, D. Meissner, N. S. Sariciftci, T. Fromherz, M. T. Rispens, L. Sanchez, and J. C. Hummelen, “Origin of the Open Circuit Voltage of Plastic Solar Cells”, Adv. Fun. Mater., 11, 374 (2001).
[6] C. Brabec, V. Dyakonov, J. Parisi, and N. S. Sariciftci, “Organic Photovoltaics”, SPRINGER (2003).
[1] H. Sirringhaus, P. J. Brown, R. H. Friend, M. M. Nielsen, K. Bechgaaed, B. M. W. Langeveld-Voss, A. J. H. Spiering, R. A. J. Janssen,E. W. Meijer, P. Herwig, and D. M. de Leeuw, “Two-dimensional charge transport in self-organized, high-mobility conjugated polymers”, Nature, 401, 685 (1999).
[2] C. M. Bjorstrom, A. Bernasik, J. Rysz, A. Budkowski, S. Nilsson, M. Svensson, M. R. Andersson, K. O. Magnusson and E. Moons “Multilayer formation in spin-coated thin films of low-bandgap polyfluorene : PCBM blends”, J. Phys.: Condens. Matter, 17, 529 (2005).
[3] J. H. Scho¨n, S. Berg, Ch. Kloc, and B. Batlogg, “Ambipolar Pentacene Field-Effect Transistors and Inverters” Science, 287, 1022 (2000).
[4] M. Ishii, T. Mori, H. Fujikawa, S. Tokito, and Y. Taga, “Organic electroluminescent devices using alkaline-earth fluorides as an electron injection layer”, J. Lumin. , 87, 1165 (2000).
[1] Y. Kim, S. A. Choulis, J. Nelson, D. D. C. Bradley, “Composition and annealing effects in polythiophene/ fullerene solar cells”, J. Mater. Sci., 40, 1371 ( 2005).
[2] K. Inoue, R. Ulbricht, P. C. Madakasira, W. M. Sampson, S. Lee, J. Gutierrez, J. P. Ferraris and A. A. Zakhidov, “Temperature and time dependence of heat treatment of RR-P3HT/PCBM solar cell”, Synth. Met., 154, 41 (2005).
[3] G. Li, V. Shortriya, Y. Yao and Y. Yang, “Investigation of annealing effects and film thickness dependence of polymer solar cells based on poly(3-hexylthiophene)”, J. Appl. Phys, 98, 043704 (2005).
[4] R. Österbacka, C. P. An, X. M. Jiang and Z. V. Vardeny, “Two-Dimensional Electronic Excitations in Self-Assembled Conjugated Polymer Nanocrystals”, Science 287, 839 (2000).
[5] X. N. Yang, J. Loos, S. C. Veenstra, W. J. H. Verhees, M. M. Wienk, J. M. Kroon, M. A. J. Michels, R. A. J. Janssen, “Nanoscale morphology of high-performance polymer solar cells”, Nano Letters., 5, 579 (2005).
[6] A. K. Pandey, P. E. Shaw, I. D. W. Samuel, J. M. Nunzi, “Effect of metal cathode reflectance on the exciton-dissociation efficiency in heterojunction organic solar cells”, Appl. Phys. Lett., 94, 103303 (2009).
[7] U. Zhokhavets, T. Erb, G. Gobsch, M. Al-Ibrahim, O. Ambacher, “Relation between absorption and crystallinity of poly(3-hexylthiophene)/fullerene films for plastic solar cells”, Chem. Phys. Lett, 418, 347 (2006).
[8] M. A. Lampert, P. Mark, “Current Injection in Solids”, Academic Press (1970).
[9] Melzer, C., Koop, E. J., Mihailetchi, V. D. & Blom, P.W. M., “Hole transport in poly(phenylenevinylene)/methanofullerene bulk-heterojunction solar cells”, Adv. Funct. Mater., 14, 865 (2004).
[1] G. Li, V. Shrotriya, J. Huang, Y. Yao, T. Moriarty, K. Emery, and Y. Yang, “High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends”, Nat. Mater., 4, 864 (2005).
[2] W. Ma, C. Yang, X. Gong, K. Lee, and A. J. Heeger, “Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology”, Adv. Func. Mater., 15, 1617 (2005).