小分子（Small molecule）有機光伏打電池（Organic photovoltaic, OPV）近年來是有機光電領域的熱門研究主題之一。本論文將多層膜微共振腔（Micro cavity）電極結合本實驗團隊具最高效率，以Donor-Acceptor-Acceptor（D-A-A）小分子有機材料2-[(7-{4-[N,N-Bis(4-methylphenyl)amino]phenyl}-2,1,3-benzothiadiazol-4-yl)methylene]propanedinitrile（DTDCPB）作為施體材料及C70作為受體材料，所製備而成之標準有機光伏元件，分別結合二組多層膜微共振腔電極，Ag/Hexaazatriphenylenehexacarbonitrile (HATCN)/Ag與Ag/Molybdenum trioxide (MoO3)/Ag，藉由精準地調變共振腔金屬層及光學間隔層厚度，成功地控制穿透過有機光伏元件之光波段，實現具可視穿變色電極之有機光伏元件製作。 在相同有機光伏系統下，透過光學工程模擬軟體Semiconductor Emission Thin Film Optics Simulation（Setfos）預測二組具多層膜電極光伏元件結構之光學特性，接著實際製成光伏元件，量測其在AM 1.5G環境下之光電流及外部量子效率表現以及元件整體光學穿透度（Transmittance），最後分別將二組元件實驗表現與模擬結果互相比較並分析探討。

Small molecular organic photovoltaic (OPV) has been one of the popular research topics in the field of organic optoelectronics in recent years. In this work, a microcavity-forming multilayered electrode was integrated with a highly efficient reference organic photovoltaic device of our research team, in which Donor-Acceptor-Acceptor (D-A-A) type small molecular organic material 2-[(7-{4-[N,N-Bis(4-methylphenyl)amino]phenyl}-2,1,3-benzothiadiazol-4-yl)methylene]propanedinitrile (DTDCPB) was used as a donor material and C70 as an acceptor material respectively. Two types of organic photovoltaic devices were fabricated by integrating two kinds of microcavity-forming multilayered electrodes, Ag/Hexaazatriphenylenehexacarbonitrile (HATCN)/Ag and Ag/Molybdenum trioxide (MoO3)/Ag separately. By precisely modulating the thickness of the metal layer and the optical spacer layer of the multilayered film, we successfully controlled the light band that penetrated the organic photovoltaic device to realize the fabrication of organic photovoltaic device with color-changing, see-through electrodes. Under the same organic photovoltaic condition, the optical properties of the two sets of photovoltaic devices with multilayered electrode were simulated by the optical engineering simulation software – ‘Semiconductor Emission Thin Film Optics Simulation’ (Setfos), and then the devices were fabricated based on the simulation results. The photocurrent and external quantum efficiency of the device under AM 1.5G illumination and the overall optical transmittance were measured. Finally, the device performance of the two sets of OPVs from simulation and experimental results were compared and analyzed respectively.

[1] E. Sanz-Casado, J.C. Garcia-Zorita, A.E. Serrano-Lopez, B. Larsen, P. Ingwersen, “Renewable energy research 1995-2009: A case study of wind power research in eu, spain, germany and denmark,” Scientometrics, vol. 95, pp. 197-224 (2013).
[2] C. Lacchini, R. Ruther, “The influence of government strategies on the financial return of capital invested in pv systems located in different climatic zones in brazil,” Renew. Energ., vol. 83, pp. 786-798 (2015).
[3] N. S. Lewis, “Toward cost-effective solar energy use,” Science, vol. 315, pp. 798-801 (2007).
[4] S. R. Forrest, P. E. Burrows, Z. Shen, G. Gu, V. Bulovic, M. E. Thompson, “The stacked oled (soled): A new type of organic device for achieving high-resolution full-color displays,” Synthetic Met., vol. 91, pp. 9-13 (1997).
[5] G. R. Chaji, C. Ng, A. Nathan, A. Werner, J. Birnstock, O. Schneider, J. Blochwitz-Nimoth, “Electrical compensation of oled luminance degradation,” Ieee Electr. Device Lett., vol. 28, pp. 1108-1110 (2007).
[6] M. Muccini, “A bright future for organic field-effect transistors,” Nat. Mater., vol. 5, pp. 605-613 (2006).
[7] Y. Shao, Y. Yang, “Efficient organic heterojunction photovoltaic cells based on triplet materials,” Adv. Mater., vol. 17, pp. 2841-2844 (2005).
[8] I. Visoly-Fisher, A. Mescheloff, M. Gabay, C. Bounioux, L. Zeiri, M. Sansotera, A.E. Goryachev, A. Braun, Y. Galagan, E.A. Katz, “Concentrated sunlight for accelerated stability testing of organic photovoltaic materials: Towards decoupling light intensity and temperature,” Sol. Energ. Mat. Sol. C., vol. 134, pp. 99-107 (2015).
[9] S. E. Shaheen, C. J. Brabec, N. S. Sariciftci, F. Padinger, T. Fromherz, J. C. Hummelen, “2.5% efficient organic plastic solar cells,” Appl. Phys. Lett., vol. 78, pp. 841-843 (2001).
[10] S. R. Forrest, “Ultrathin organic films grown by organic molecular beam deposition and related techniques,” Chem. Rev., vol. 97, pp. 1793-1896 (1997).
[11] C. J. M. Emmott, J. A. Röhr, M. Campoy-Quiles, T. Kirchartz, A. Urbina, N. J. Ekins-Daukes, J. Nelson, “Organic photovoltaic greenhouses: A unique application for semi-transparent pv?,” Energy Environ. Sci., vol. 8, pp. 1317-1328 (2015).
[12] F. C. Krebs, “All solution roll-to-roll processed polymer solar cells free from indium-tin-oxide and vacuum coating steps,” Org. Electron., vol. 10, pp. 761-768 (2009).
[13] M. Manceau, D. Angmo, M. Jorgensen, F. C. Krebs, “Ito-free flexible polymer solar cells: From small model devices to roll-to-roll processed large modules,” Org. Electron., vol. 12, pp. 566-574 (2011).
[14] D. Angmo, T. T. Larsen-Olsen, M. Jorgensen, R. R. Sondergaard, F. C. Krebs, “Roll-to-roll inkjet printing and photonic sintering of electrodes for ito free polymer solar cell modules and facile product integration,” Adv. Energy Mater., vol. 3, pp. 172-175 (2013).
[15] J. M. Ball, M. M. Lee, A. Hey, H. J. Snaith, “Low-temperature processed meso-superstructured to thin-film perovskite solar cells,” Energy Environ. Sci., vol. 6, pp. 1739-1743 (2013).
[16] M. Riede, T. Mueller, W. Tress, R. Schueppel, K. Leo, “Small-molecule solar cells - status and perspectives,” Nanotechnology, vol. 19 (2008).
[17] Y. P. Yi, V. Coropceanu, J. L. Bredas, “Exciton-dissociation and charge-recombination processes in pentacene/C60 solar cells: Theoretical insight into the impact of interface geometry,” J. Am. Chem. Soc., vol. 131, pp. 15777-15783 (2009).
[18] P. B. Miranda, D. Moses, A. J. Heeger, “Ultrafast photogeneration of charged polarons in conjugated polymers,” Phys Rev B, vol. 64 (2001).
[19] R. Sokel, R. Hughes, “Numerical analysis of transient photoconductivity in insulators,” J. Appl. Phys., vol. 53, pp. 7414-7424 (1982).
[20] D. L. Pulfrey, “Photovoltaic power generation,” New York, Van Nostrand Reinhold Co., 230 p.22 (1978).
[21] D. Kearns, M. Calvin, “Photovoltaic effect and photoconductivity in laminated organic systems,” J. Chem. Phys., vol. 29, pp. 950-951 (1958).
[22] C. Tang, A. Albrecht, “Photovoltaic effects of metal–chlorophyll‐a–metal sandwich cells,” J. Chem. Phys., vol. 62, pp. 2139-2149 (1975).
[23] D. Wöhrle, D. Meissner, “Organic solar cells,” Adv. Mater., vol. 3, pp. 129-138 (1991).
[24] C. W. Tang, “Two‐layer organic photovoltaic cell,” Appl. Phys. Lett., vol. 48, pp. 183-185 (1986).
[25] P. Peumans, V. Bulovic, S. R. Forrest, “Efficient photon harvesting at high optical intensities in ultrathin organic double-heterostructure photovoltaic diodes,” Appl. Phys. Lett., vol. 76, pp. 2650-2652 (2000).
[26] H. Kurczewska, H. Bässler, “Energy transfer across an anthracene-gold interface,” J. Lumin., vol. 15, pp. 261-266 (1977).
[27] V. Choong, Y. Park, Y. Gao, T. Wehrmeister, K. Mullen, B. R. Hsieh, C. W. Tang, “Dramatic photoluminescence quenching of phenylene vinylene oligomer thin films upon submonolayer ca deposition,” Appl. Phys. Lett., vol. 69, pp. 1492-1494 (1996).
[28] V. E. Choong, Y. Park, Y. L. Gao, B. R. Hsieh, C. W. Tang, “Metal induced photoluminescence quenching of a phenylene vinylene oligomer and its recovery,” Macromol. Symp., vol. 125, pp. 83-97 (1998).
[29] D. F. O'Brien, M. A. Baldo, M. E. Thompson, S. R. Forrest, “Improved energy transfer in electrophosphorescent devices,” Appl. Phys. Lett., vol. 74, pp. 442-444 (1999).
[30] G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, “Polymer photovoltaic cells - enhanced efficiencies via a network of internal donor-acceptor heterojunctions,” Science, vol. 270, pp. 1789-1791 (1995).
[31] B. P. Rand, J. G. Xue, F. Yang, S. R. Forrest, “Organic solar cells with sensitivity extending into the near infrared - art. No. 200508,” Appl. Phys. Lett., vol. 87, pp. (2005).
[32] T. Tsuzuki, Y. Shirota, J. Rostalski, D. Meissner, “The effect of fullerene doping on photoelectric conversion using titanyl phthalocyanine and a perylene pigment,” Sol. Energ. Mat. Sol. C., vol. 61, pp. 1-8 (2000).
[33] S. Uchida, J. Xue, B. P. Rand, S. R. Forrest, “Organic small molecule solar cells with a homogeneously mixed copper phthalocyanine: C60 active layer,” Appl. Phys. Lett., vol. 84, pp. 4218-4220 (2004).
[34] P. Peumans, S. Uchida, and S. R. Forrest, "Efficient bulk heterojunction photovoltaic cells using small-molecular-weight organic thin films," Nature, vol. 425, pp. 158-162 (2003).
[35] M. Hiramoto, H. Fujiwara, M. Yokoyama, “Three‐layered organic solar cell with a photoactive interlayer of codeposited pigments,” Appl. Phys. Lett., vol. 58, pp. 1062-1064 (1991).
[36] M. Hiramoto, H. Fujiwara, M. Yokoyama, “P‐i‐n like behavior in three‐layered organic solar cells having a co‐deposited interlayer of pigments,” J. Appl. Phys., vol. 72, pp. 3781-3787 (1992).
[37] J. G. Xue, B. P. Rand, S. Uchida, S. R. Forrest, “A hybrid planar-mixed molecular heterojunction photovoltaic cell,” Adv. Mater., vol. 17, pp. 66-71 (2005).
[38] D. Gebeyehu, B. Maennig, J. Drechsel, K. Leo, M. Pfeiffer, “Bulk-heterojunction photovoltaic devices based on donor–acceptor organic small molecule blends,” Sol. Energ. Mat. Sol. C., vol. 79, pp. 81-92 (2003).
[39] S. Yoo, B. Domercq, B. Kippelen, “Efficient thin-film organic solar cells based on pentacene/C60 heterojunctions,” Appl. Phys. Lett., vol. 85, pp. 5427-5429 (2004).
[40] C. W. Chu, Y. Shao, V. Shrotriya, Y. Yang, “Efficient photovoltaic energy conversion in tetracene-C60 based heterojunctions,” Appl. Phys. Lett., vol. 86, pp. 243506 (2005).
[41] K. Cnops, B. P. Rand, D. Cheyns, B. Verreet, M. A. Empl, P. Heremans, “8.4% efficient fullerene-free organic solar cells exploiting long-range exciton energy transfer,” Nat. Commun., vol. 5 (2014).
[42] S. M. Menke, R. J. Holmes, “Energy-cascade organic photovoltaic devices incorporating a host-guest architecture,” Acs Appl. Mater. Inter., vol. 7, pp. 2912-2918 (2015).
[43] R. F. Salzman, J. G. Xue, B. P. Rand, A. Alexander, M. E. Thompson, S.R. Forrest, “The effects of copper phthalocyanine purity on organic solar cell performance,” Org. Electron., vol. 6, pp. 242-246 (2005).
[44] H. Kumar, P. Kumar, R. Bhardwaj, G. D. Sharma, S. Chand, S. C. Jain, V. Kumar, “Broad spectral sensitivity and improved efficiency in CuPc/Sub-Pc organic photovoltaic devices,” J. Phys. D-Appl. Phys., vol. 42, pp. 015103 (2009).
[45] H. W. Kroto, J. R. Heath, S. C. O'Brien, R. F. Curl, R. E. Smalley, “C60: Buckminsterfullerene,” Nature, vol. 318, pp. 162-163 (1985).
[46] N. S. Sariciftci, L. Smilowitz, A. J. Heeger, F. Wudl, “Photoinduced electron transfer from a conducting polymer to buckminsterfullerene,” Science, vol. 258, pp. 1474-1476 (1992).
[47] E. Frankevich, Y. Maruyama, H. Ogata, “Mobility of charge carriers in vapor-phase grown C60 single crystal,” Chem. Phys. Lett., vol. 214, pp. 39-44 (1993).
[48] L. A. A. Pettersson, L. S. Roman, O. Inganas, “Modeling photocurrent action spectra of photovoltaic devices based on organic thin films,” J. Appl. Phys., vol. 86, pp. 487-496 (1999).
[49] G. D. Han, W. R. Collins, T. L. Andrew, V. Bulović, T. M. Swager, “Cyclobutadiene–C60 adducts: N‐type materials for organic photovoltaic cells with high VOC,” Adv. Funct. Mater., vol. 23, pp. 3061-3069 (2013).
[50] F. Roth, C. Lupulescu, T. Arion, E. Darlatt, A. Gottwald, W. Eberhardt, “Electronic properties and morphology of Cu-phthalocyanine—C60 composite mixtures,” J. Appl. Phys., vol. 115, pp. 033705 (2014).
[51] J. Yang, T. Q. Nguyen, “Effects of thin film processing on pentacene/C60 bilayer solar cell performance,” Org. Electron., vol. 8, pp. 566-574 (2007).
[52] S. Pfuetzner, J. Meiss, A. Petrich, M. Riede, K. Leo, “Improved bulk heterojunction organic solar cells employing C70 fullerenes,” Appl. Phys. Lett., vol. 94, pp. 223307 (2009).
[53] J. Sakai, T. Taima, T. Yamanari, K. Saito, “Annealing effect in the sexithiophene: C70 small molecule bulk heterojunction organic photovoltaic cells,” Sol. Energ. Mat. Sol. C., vol. 93, pp. 1149-1153 (2009).
[54] X. Xi, W. Li, J. Wu, J. Ji, Z. Shi, G. Li, “A comparative study on the performances of small molecule organic solar cells based on CuPc/C60 and CuPc /C70,” Sol. Energ. Mat. Sol. C., vol. 94, pp. 2435-2441 (2010).
[55] P. Peumans, S. Forrest, “Very-high-efficiency double-heterostructure copper phthalocyanine/C60 photovoltaic cells,” Appl. Phys. Lett., vol. 79, pp. 126-128 (2001).
[56] M. Vogel, S. Doka, C. Breyer, M.C. Lux-Steiner, K. Fostiropoulosa, “On the function of a bathocuproine buffer layer in organic photovoltaic cells,” Appl. Phys. Lett., vol. 89, pp. 163501-3 (2006).
[57] K. Kuhnke, R. Becker, M. Epple, K. Kern, “C60 exciton quenching near metal surfaces,” Physical Review Letters, vol. 79, pp. 3246-3249 (1997).
[58] H. R. Wu, M. L. Wang, Q. L. Song, Y. Wu, Z.T. Xie, X.D. Gao, X. M. Ding, X.Y. Hou, “Short-circuiting in fullerene devices studied by in situ electrical measurement in high vacuum and infrared imaging analysis,” Curr. Appl. Phys., vol. 7, pp. 231-235 (2007).
[59] H. X. Wei, J. Li, Y. Cai, Z.Q. Xu, S. T. Lee, Y.Q. Li, J.X. Tang, “Electronic structures of planar and mixed C70/CuPc heterojunctions in organic photovoltaic devices,” Org. Electron., vol. 12, pp. 1422-1428 (2011).
[60] M. Kroger, S. Hamwi, J. Meyer, T. Riedl, W. Kowalsky, A. Kahn, “Role of the deep-lying electronic states of MoO3 in the enhancement of hole-injection in organic thin films,” Appl. Phys. Lett., vol. 95, pp. 123301 (2009).
[61] K. V. Chauhan, P. Sullivan, J. L. Yang, T.S. Jones, “Efficient organic photovoltaic cells through structural modification of chloroaluminum phthalocyanine/fullerene heterojunctions,” J. Phys. Chem. C, vol. 114, pp. 3304-3308 (2010).
[62] I. Hancox, K. V. Chauhan, P. Sullivan, R. A. Hatton, A. Moshar, C.P.A. Mulcahy, T.S. Jones, “Increased efficiency of small molecule photovoltaic cells by insertion of a MoO3 hole-extracting layer,” Energy Environ. Sci., vol. 3, pp. 107-110 (2010).
[63] A. K. K. Kyaw, X. W. Sun, C. Y. Jiang, G.Q. Lo, D. W. Zhao, D. L. Kwong, “An inverted organic solar cell employing a sol-gel derived zno electron selective layer and thermal evaporated moo3 hole selective layer,” Appl. Phys. Lett., vol. 93, pp. 3 (2008).
[64] G. Gu, V. Bulović, P. E. Burrows, S. R. Forrest, M. E. Thompson, “Transparent organic light emitting devices,” Appl. Phys. Lett., vol. 68, pp. 2606-2608 (1996).
[65] M. Zadsar, H. R. Fallah, M. H. Mahmoodzadeh, S. V. Tabatabaei, “The effect of ag layer thickness on the properties of WO3/Ag/MoO3 multilayer films as anode in organic light emitting diodes,” J. Lumin., vol. 132, pp. 992-997 (2012).
[66] K. Jeon, H. Youn, S. Kim, S. Shin, M. Yang, “Fabrication and characterization of WO3/Ag/WO3 multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes,” Nanoscale Res. Lett., vol. 7, pp. 253 (2012).
[67] K. H. Choi, J. Y. Kim, Y. S. Lee, H. J. Kim, “ITO/Ag/ITO multilayer films for the application of a very low resistance transparent electrode,” Thin Solid Films, vol. 341, pp. 152-155 (1999).
[68] Y. H. Chen, C. W. Chen, Z. Y. Huang, W. C. Lin, L. Y. Lin, F. Lin, K. T. Wong, H. W. Lin, “Microcavity-embedded, colour-tuneable, transparent organic solar cells,” Adv. Mater., vol. 26, pp. 1129-1134 (2014).
[69] K. T. Lee, M. Fukuda, S. Joglekar, L. J. Guo, “Colored, see-through perovskite solar cells employing an optical cavity,” J. Mater. Chem. C, vol. 3, pp. 5377-5382 (2015).
[70] J. H. Lu, Y. L. Yu, S. R. Chuang, C. H. Yeh, C. P. Chen, “High-performance, semitransparent, easily tunable vivid colorful perovskite photovoltaics featuring Ag/ITO/Ag microcavity structures,” J. Phys. Chem. C, vol. 120, pp. 4233-4239 (2016).
[71] J. H. Lu, Y. H. Lin, B. H. Jiang, C. H. Yeh, J. C. Kao, C. P. Chen, “Microcavity structure provides high-performance (>8.1%) semitransparent and colorful organic photovoltaics,” Adv. Funct. Mater., vol. 28, pp. 1703398 (2018).
[72] I. G. Hill, A. Kahn, Z. G. Soos, J. R. A. Pascal, “Charge-separation energy in films of π-conjugated organic molecules,” Chem. Phys. Lett., vol. 327, pp. 181-188 (2000).
[73] S. B. Rim, R. F. Fink, J. C. Schoneboom, P. Erk, P. Peumans, “Effect of molecular packing on the exciton diffusion length in organic solar cells,” Appl. Phys. Lett., vol. 91, pp. 173504-3 (2007).
[74] B. Leckner, “The spectral distribution of solar radiation at the earth's surface—elements of a model,” Solar Energy, vol. 20, pp. 143-150 (1978).
[75] P. Peumans, A. Yakimov, S. R. Forrest, “Small molecular weight organic thin-film photodetectors and solar cells,” J. Appl. Phys., vol. 93, pp. 3693-3723 (2003).
[76] A. Jannat, M. Rahman, M. Saddam Hossain khan, A review study of organic photovoltaic cell (2013).
[77] B. P. Rand, J. Genoe, P. Heremans, J. Poortmans, “Solar cells utilizing small molecular weight organic semiconductors,” Prog. Photovoltaics, vol. 15, pp. 659-676 (2007).
[78] C. Kulshreshtha, J. W. Choi, J. K. Kim, W. S. Jeon, M. C. Suh, Y. Park, J. H. Kwon, “Open-circuit voltage dependency on hole-extraction layers in planar heterojunction organic solar cells,” Appl. Phys. Lett., vol. 99, pp. 023308 (2011).
[79] B. P. Rand, D. P. Burk, S. R. Forrest, “Offset energies at organic semiconductor heterojunctions and their influence on the open-circuit voltage of thin-film solar cells,” Phys Rev B, vol. 75, pp. 113527 (2007).
[80] H. Hoppe, N. S. Sariciftci, “Organic solar cells: An overview,” J. Mater. Res., vol. 19, pp. 1924-1945 (2004).
[81] D. Gupta, S. Mukhopadhyay, K. S. Narayan, “Fill factor in organic solar cells,” Sol. Energ. Mat. Sol. C., vol. 94, pp. 1309-1313 (2010).
[82] N. Li, B. E. Lassiter, R. R. Lunt, G. Wei, S.R. Forrest, “Open circuit voltage enhancement due to reduced dark current in small molecule photovoltaic cells,” Appl. Phys. Lett., vol. 94 (2009).
[83] X. R. Tong, B. E. Lassiter, S. R. Forrest, “Inverted organic photovoltaic cells with high open-circuit voltage,” Org. Electron., vol. 11, pp. 705-709 (2010).
[84] M. A. Loi, S. Toffanin, M. Muccini, M. Forster, U. Scherf, M. Scharber, “Charge transfer excitons in bulk heterojunctions of a polyfluorene copolymer and a fullerene derivative,” Adv. Funct. Mater., vol. 17, pp. 2111-2116 (2007).
[85] K. Tvingstedt, K. Vandewal, A. Gadisa, F.L. Zhang, J. Manca, O. Inganas, “Electroluminescence from charge transfer states in polymer solar cells,” J. Am. Chem. Soc., vol. 131, pp. 11819-11824 (2009).
[86] L. Goris, K. Haenen, M. Nesladek, P. Wagner, D. Vanderzande, L. De Schepper, J. D'Haen, L. Lutsen, J. V. Manca, “Absorption phenomena in organic thin films for solar cell applications investigated by photothermal deflection spectroscopy,” J. Mater. Sci., vol. 40, pp. 1413-1418 (2005).
[87] J. Niklas, O. G. Poluektov, “Charge transfer processes in opv materials as revealed by epr spectroscopy,” Adv. Energy Mater., vol. 7, pp. 1602226 (2017).
[88] N. P. Sergeant, A. Hadipour, B. Niesen, D. Cheyns, P. Heremans, P. Peumans, B.P. Rand, “Design of transparent anodes for resonant cavity enhanced light harvesting in organic solar cells,” Adv. Mater., vol. 24, pp. 728-732 (2012).
[89] H. Jin, C. Tao, M. Velusamy, M. Aljada, Y. Zhang, M. Hambsch, P.L. Burn, P. Meredith, “Efficient, large area ito-and-pedot-free organic solar cell sub-modules,” Adv. Mater., vol. 24, pp. 2572-2577 (2012).