利用聚苯乙烯微球作為犧牲式模板製備多孔性對電極，沈積於全無機金屬氧化物結構上，並將其應用於鈣鈦礦太陽能電池，避免使用有機載子傳輸層並且讓沉積鈣鈦礦作為製程的最後一步，可移除有機載子傳輸層的不穩定性並且可以避免沈積無機載子傳輸層對鈣鈦礦主動層的影響，此元件結構具備基板回收的特性，透過DMF溶劑清洗去除鈣鈦礦後，可以再次沉積新的鈣鈦礦於基板上，重新製成電池，可降低製造成本。
　
　　此篇研究中主要將多孔電極應用於背接觸式電池以及傳統單一片式電池，其元件結構如下FTO/ c-TiO2/SnO2/Al2O3/ NiOx/Au/NiOx /Triple cation PSK，透過熱蒸鍍將鋁、金和鎳等金屬依序沉積在基板上，利用THF溶劑與超音波震盪的方式去除聚苯乙烯球模板形成多孔電極，再進行高溫燒結使金屬氧化，最後沉積鈣鈦礦後即成為電池，元件具有光電轉換效率為1.48%。此研究的電池結構具可回收性、無機金屬氧化物架構以及適合大面積製造等具備商業化量產的潛力。

Monolayer closely-packed polystyrene microspheres (PSS) serve as a sacrificial template for fabrication of porous counter electrodes. An ordered array of pores is created to form an counter electrodes after reducing the microsphere size, deposition of metal-oxide layer and removal of PSS sequentially. The porous counter electrode is deposited onto the inorganic metal-oxide layers to become an all-inorganic metal oxide structure. Such device structure avoids the use of organic carrier transport layers and allows deposition of perovskites as the final step in the process. In this study, porous electrodes are employed in quasi-interdigitated back-contact (QIBC) perovskite solar cells with a structure of TiO2/SnO2/Al2O3/nanoporous (np)-Au:NiOx. After optimizing the porosity and conductivity of metal porous counter electrode, the power conversion efficiency of the device can reach 1.48%. Such device structure has the potential to be commercialized with the advantages of recyclability, inorganic metal oxide structure and large-area manufacturing.

1. Becquerel, A. E., Recherches sur les effets de la radiation chimique de la lumiere solaire au moyen des courants electriques. Comptes Rendus de L´Academie des Sciences 1839, 9, 145-149.
2. Grätzel, M., Dye-sensitized solar cells. Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2003, 4, 145-153.
3. NREL, Best Research-Cell Efficiency Chart. 2019.
4. Reference Solar Spectral Irradiance: Air Mass 1.5, American Society for Testing and Materials (ASTM) Terrestrial Reference Spectra for BR Photovoltaic Performance Evaluation.
5. M. Pagliaro, G. Palmisano, and R. Ciriminna, Flexible Solar Cells, John Wiley & Sons, New York, 2008.
6. Pindado, S.; Cubas, J.; De Manuel, C., Explicit Expressions for Solar Panel Equivalent Circuit Parameters Based on Analytical Formulation and the Lambert W-Function. 2014, Vol. 7, 4098-4115.
7. Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T., Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. Journal of the American Chemical Society 2009, 131, 6050-6051.
8. Correa Baena, J. P.; Steier, L.; Tress, W.; Saliba, M.; Neutzner, S.; Matsui, T.; Giordano, F.; Jacobsson, T. J.; Srimath Kandada, A. R.; Zakeeruddin, S. M.; Petrozza, A.; Abate, A.; Nazeeruddin, M. K.; Grätzel, M.; Hagfeldt, A., Highly efficient planar perovskite solar cells through band alignment engineering. Energy & Environmental Science 2015, 8, 2928-2934.
9. Saliba, M.; Matsui, T.; Seo, J.-Y.; Domanski, K.; Correa-Baena, J.-P.; Nazeeruddin, M. K.; Zakeeruddin, S. M.; Tress, W.; Abate, A.; Hagfeldt, A.; Grätzel, M., Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency. Energy & Environmental Science 2016, 9, 1989-1997.
10. Kay, A.; Grätzel, M., Low cost photovoltaic modules based on dye sensitized nanocrystalline titanium dioxide and carbon powder. Solar Energy Materials and Solar Cells 1996, 44, 99-117.
11. Bach, U.; Lupo, D.; Comte, P.; Moser, J. E.; Weissortel, F.; Salbeck, J.; Spreitzer, H.; Gratzel, M., Solid-state dye-sensitized mesoporous TiO2 solar cells with high photon-to-electron conversion efficiencies. Nature 1998, 395, 583-585.
12. Ito, S.; Takahashi, K., Fabrication of Monolithic Dye-Sensitized Solar Cell Using Ionic Liquid Electrolyte. International Journal of Photoenergy 2012, 915352.
13. Ku, Z.; Rong, Y.; Xu, M.; Liu, T.; Han, H., Full printable processed mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cells with carbon counter electrode. Scientific reports 2013, 3, 3132.
14. Kroon, J. M.; Bakker, N. J.; Smit, H. J. P.; Liska, P.; Thampi, K. R.; Wang, P.; Zakeeruddin, S. M.; Grätzel, M.; Hinsch, A.; Hore, S.; Würfel, U.; Sastrawan, R.; Durrant, J. R.; Palomares, E.; Pettersson, H.; Gruszecki, T.; Walter, J.; Skupien, K.; Tulloch, G. E., Nanocrystalline dye-sensitized solar cells having maximum performance. Progress in Photovoltaics: Research and Applications 2007, 15, 1-18.
15. Kashiwa, Y.; Yoshida, Y.; Hayase, S., All-metal-electrode-type dye sensitized solar cells (transparent conductive oxide-less dye sensitized solar cell) consisting of thick and porous Ti electrode with straight pores. Applied Physics Letters 2008, 92, 033308.
16. Yoo, B.; Kim, K.-J.; Kim, Y. H.; Kim, K.; Ko, M. J.; Kim, W. M.; Park, N.-G., Titanium nitride thin film as a novel charge collector in TCO-less dye-sensitized solar cell. Journal of Materials Chemistry 2011, 21, 3077.
17. Shen, P.-S.; Li, M.-H.; Yang, Y.-S.; Sung-Yen Juang, S.; Lin, C.-W.; Yin, T.-Y.; Chen, P., A novel porous Ti/TiN/Ti thin film as a working electrode for back-contact, monolithic and non-TCO dye-sensitized solar cells. Sustainable Energy & Fuels 2017, 1, 851-858.
18. Mei, A.; Li, X.; Liu, L.; Ku, Z.; Liu, T.; Rong, Y.; Xu, M.; Hu, M.; Chen, J.; Yang, Y.; Gratzel, M.; Han, H., A hole-conductor-free, fully printable mesoscopic perovskite solar cell with high stability. Science 2014, 345, 295-8.
19. Liu, Z.; Zhang, M.; Xu, X.; Bu, L.; Zhang, W.; Li, W.; Zhao, Z.; Wang, M.; Cheng, Y. B.; He, H., p-Type mesoscopic NiO as an active interfacial layer for carbon counter electrode based perovskite solar cells. Dalton transactions 2015, 44, 3967-73.
20. Zhou, X.; Bao, C.; Li, F.; Gao, H.; Yu, T.; Yang, J.; Zhu, W.; Zou, Z., Hole-transport-material-free perovskite solar cells based on nanoporous gold back electrode. RSC Advances 2015, 5, 58543-58548.
21. Ku, Z.; Xia, X.; Shen, H.; Tiep, N. H.; Fan, H. J., A mesoporous nickel counter electrode for printable and reusable perovskite solar cells. Nanoscale 2015, 7, 13363-13368.
22. Li, H.; Cao, K.; Cui, J.; Liu, S.; Qiao, X.; Shen, Y.; Wang, M., 14.7% efficient mesoscopic perovskite solar cells using single walled carbon nanotubes/carbon composite counter electrodes. Nanoscale 2016, 8, 6379-85.
23. Tsai, C.-M.; Wu, G.-W.; Narra, S.; Chang, H.-M.; Mohanta, N.; Wu, H.-P.; Wang, C.-L.; Diau, E. W.-G., Control of preferred orientation with slow crystallization for carbon-based mesoscopic perovskite solar cells attaining efficiency 15%. J. Mater. Chem. A 2017, 5, 739-747.
24. Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; De Angelis, F.; Graetzel, M.; Nazeeruddin, M. K., One-Year stable perovskite solar cells by 2D/3D interface engineering. 2017, 8, 15684.
25. Jumabekov, A. N.; Della Gaspera, E.; Xu, Z. Q.; Chesman, A. S. R.; van Embden, J.; Bonke, S. A.; Bao, Q.; Vak, D.; Bach, U., Back-contacted hybrid organic–inorganic perovskite solar cells. Journal of Materials Chemistry C 2016, 4, 3125-3130.
26. Hou, Q.; Bacal, D.; Jumabekov, A. N.; Li, W.; Wang, Z.; Lin, X.; Ng, S. H.; Tan, B.; Bao, Q.; Chesman, A. S. R.; Cheng, Y.-B.; Bach, U., Back-contact perovskite solar cells with honeycomb-like charge collecting electrodes. Nano Energy 2018, 50, 710-716.
27. Lin, X.; S. R. Chesman, A.; Ruiz Raga, S.; Scully, A.; Liangcong, J.; Tan, B.; Lu, J.; Cheng, Y.-B.; Bach, U., Effect of Grain Cluster Size on Back-Contact Perovskite Solar Cells. 2018, 28, 1805098.
28. DeLuca, G.; Jumabekov, A. N.; Hu, Y.; Simonov, A. N.; Lu, J.; Tan, B.; Adhyaksa, G. W. P.; Garnett, E. C.; Reichmanis, E.; Chesman, A. S. R.; Bach, U., Transparent Quasi-Interdigitated Electrodes for Semitransparent Perovskite Back-Contact Solar Cells. ACS Applied Energy Materials 2018, 1, 4473-4478.
29. Rong, Y.; Ku, Z.; Mei, A.; Liu, T.; Xu, M.; Ko, S.; Li, X.; Han, H., Hole-Conductor-Free Mesoscopic TiO2/CH3NH3PbI3 Heterojunction Solar Cells Based on Anatase Nanosheets and Carbon Counter Electrodes. The Journal of Physical Chemistry Letters 2014, 5, 2160-2164.
30. Mei, A.; Li, X.; Liu, L.; Ku, Z.; Liu, T.; Rong, Y.; Xu, M.; Hu, M.; Chen, J.; Yang, Y.; Grätzel, M.; Han, H., A hole-conductor–free, fully printable mesoscopic perovskite solar cell with high stability. Science 2014, 345, 295.
31. Zhang, L.; Liu, T.; Liu, L.; Hu, M.; Yang, Y.; Mei, A.; Han, H., The effect of carbon counter electrodes on fully printable mesoscopic perovskite solar cells. Journal of Materials Chemistry A 2015, 3, 9165-9170.
32. Liu, Z.; Zhang, M.; Xu, X.; Bu, L.; Zhang, W.; Li, W.; Zhao, Z.; Wang, M.; Cheng, Y.-B.; He, H., p-Type mesoscopic NiO as an active interfacial layer for carbon counter electrode based perovskite solar cells. Dalton transactions 2015, 44, 3967-3973.
33. Wei, Z.; Chen, H.; Yan, K.; Zheng, X.; Yang, S., Hysteresis-free multi-walled carbon nanotube-based perovskite solar cells with a high fill factor. Journal of Materials Chemistry A 2015, 3, 24226-24231.
34. Xu, X.; Liu, Z.; Zuo, Z.; Zhang, M.; Zhao, Z.; Shen, Y.; Zhou, H.; Chen, Q.; Yang, Y.; Wang, M., Hole Selective NiO Contact for Efficient Perovskite Solar Cells with Carbon Electrode. Nano Letters 2015, 15, 2402-2408.
35. Cao, K.; Zuo, Z.; Cui, J.; Shen, Y.; Moehl, T.; Zakeeruddin, S. M.; Grätzel, M.; Wang, M., Efficient screen printed perovskite solar cells based on mesoscopic TiO2/Al2O3/NiO/carbon architecture. Nano Energy 2015, 17, 171-179.
36. Liu, Z.; Zhang, M.; Xu, X.; Cai, F.; Yuan, H.; Bu, L.; Li, W.; Zhu, A.; Zhao, Z.; Wang, M.; Cheng, Y.-B.; He, H., NiO nanosheets as efficient top hole transporters for carbon counter electrode based perovskite solar cells. Journal of Materials Chemistry A 2015, 3, 24121-24127.
37. Li, H.; Cao, K.; Cui, J.; Liu, S.; Qiao, X.; Shen, Y.; Wang, M., 14.7% efficient mesoscopic perovskite solar cells using single walled carbon nanotubes/carbon composite counter electrodes. Nanoscale 2016, 8, 6379-6385.
38. Tsai, C.-M.; Wu, G.-W.; Narra, S.; Chang, H.-M.; Mohanta, N.; Wu, H.-P.; Wang, C.-L.; Diau, E. W.-G., Control of preferred orientation with slow crystallization for carbon-based mesoscopic perovskite solar cells attaining efficiency 15%. Journal of Materials Chemistry A 2017, 5, 739-747.
39. Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; De Angelis, F.; Graetzel, M.; Nazeeruddin, M. K., One-Year stable perovskite solar cells by 2D/3D interface engineering. Nature Communications 2017, 8, 15684.
40. Liu, S.; Huang, W.; Liao, P.; Pootrakulchote, N.; Li, H.; Lu, J.; Li, J.; Huang, F.; Shai, X.; Zhao, X.; Shen, Y.; Cheng, Y.-B.; Wang, M., 17% efficient printable mesoscopic PIN metal oxide framework perovskite solar cells using cesium-containing triple cation perovskite. Journal of Materials Chemistry A 2017, 5, 22952-22958.
41. Chandramohan, A.; Sibirev, N. V.; Dubrovskii, V. G.; Petty, M. C.; Gallant, A. J.; Zeze, D. A., Model for large-area monolayer coverage of polystyrene nanospheres by spin coating. Scientific reports 2017, 7, 40888.