由於二維鈣鈦礦材料的放光特性及良好的環境穩定性使得越來越多團隊
投入研究，然而目前效率及穩定性難以在單一材料兼得，二維材料雖然擁有優秀的穩定性，但因結構卻流失了電流使得元件效率不盡理想。因此近年來有團隊發表二維/三維疊層鈣鈦礦的製程，希望能在不犧牲三維鈣鈦礦良好的元件性能下，以一層薄薄的二維材料覆蓋三維結構來提升環境穩定性。
而組成二維材料的有機陽離子有非常多種選擇，機制與特性亦有些許不同，因此本研究將探討不同有機陽離子作二維結構對三維鈣鈦礦的影響。
本研究選定n-Butylammonium iodide (BAI)與n-Hexylammonium iodide(HAI)兩種有機陽離子分別旋塗於FA0.9Cs0.1PbI3 三維鈣鈦礦上，探討不同碳鏈長之分子對穩定性與元件表現的影響。研究結果證實旋塗疏水鏈更長的分子在保持三維鈣鈦礦的效率條件下能具有更佳的濕氣穩定性。
由於碳鏈越長表示分子尺寸越大，較不易擴散於三維結構中，因此能在表面形成好的水氣絕緣層，又因少許有機陽離子具有鈍化三維結構表面之特性，使得鈣鈦礦表面能降低。然而在光照穩定性的部分，加入少量有機陽離子並沒有使穩定性提高，而是需要過量的二維結構才足以使鈣鈦礦在光照下不被分解，且研究結果表明在阻絕水氣的影響下，兩種有機陽離子在光照環境下之穩定性並無太大差別。

In this study, we focus on the development of 2D/3D stacking perovskite and its application on perovskite solar cells for the aim of improving perovskite stability and device efficiency. The large-sized cation (n-butylammonium iodide, BAI and n-hexylammonium
iodide, HAI) solution was deposited on the top of FA0.9Cs0.1PbI3 perovskite thin film to form a surface passivation layer via interfacial engineering. We explore the optical and material properties of 2D/3D stacking perovskites by employing variant chain length of large-sized cations covered on the top of 3D perovskite. A lower concentration large-sized cation solution (≤16mM) can help to passivate the 3D perovskite surface,which corrosion by moisture and improve device stability. The 2D/3D stacking perovskite using large-sized cation of HAI is demonstrated a promising efficiency of 17.64%. Moreover, device exhibits about 76% of its initial PCE after aging 300h in 40%RH without encapsulated, while the pristine device only shows 47% of its initial PCE. Besides,the passivation layer with higher concentration of large-cation solution, the device shows a better stability about 78% of initial PCE after aging 50 hours.

[1] E. Becquerel, “Memoire sur les effets electriques produits sous influence des rayons solaires”, Comptes Rendus., 9, 561-567 (1839).
[2] Photograph of the world's first rooftop solar panel in 1884.
[3] M. A. Green, “Photovoltaics: coming of age; In Photovoltaic Specialists Con-ference”, Conference Record of the Twenty First IEEE, 1, 1-8 (1990).
[4] D. Archer, “Global Warming: Understanding the Forecast”, Second Edition, p.87-103 (2011).
[5] National Renewable Energy Laboratory (NREL), Golden, CO-United States Department of Energy (2019).
[6] 吳鎮國、林鴻、盧以昕、許仲成、陳欣卉、吳育任，淺談太陽能電池的原理與應用，台大電機系科普系列。
[7] A. D. Vos, "Detailed balance limit of the efficiency of tandem solar cells", J Phys D Appl Phys., 13, 839-846 (1980).
[8] J. Nelson, “The Physics of Solar Cells”, Imperial College Press., p.7-15 (2003).
[9] ASTM E927-10, Standard Specification for Solar simulation for Photovoltaic Testing, ASTM International, West Conshohocken, PA, (2015).
[10] 李御台、曾百亨，以快速硒化法製備高品質Cu2ZnSnSe4薄膜並應用於太陽電池元件，國立中山大學材料與光電科學學系碩士論文，2015。
[11] H. Sai, K. Maejima, T. Matsui, T. Koida, M. Kondo, S. Nakao, Y. Takeuchi, H. Katayama, I. Yoshida, “High-efficiency microcrystalline silicon solar cells on honeycomb textured substrates grown with high-rate VHF plasma-enhanced chemical vapor deposition”, Jpn J Appl Phys., 54, 08KB05 (2015).
[12] M. A. Arturo, “Thin film CdS/CdTe solar cells: Research perspectives”, Sol. Energ., 8, 675-681 (2006).
[13] R. Tatavarti, G. Hillier, A. Dzankovic, G. Martin, F. Tuminello, R. Navarat-narajah, G. Du, D.P. Vu, N. Pan, “Lightweight, low cost GaAs solar cells on 4 epi-taxial liftoff (ELO) wafers”, USA IEEE Photovoltaic Specialists Conference, 33rd, 2008.
[14] M. A. Green, K. Emery, Y. Hishikawa, W. Warta, E.D. Dunlop, “Solar cell effi-ciency tables (version 40)”, Prog. Photovolts., 20, 606–614 (2012).
[15] F. L. Wu, S.L. Ou, R. H. Horng, Y.C. Kao, “Improvement in separation rate of epitaxial lift-off by hydrophilic solvent for GaAs solar cell applications”, Sol. En-erg. Mat. Sol. Cells., 112, 233–240 (2014).
[16] K. Lee, J. D. Zimmerman, T. W. Hughes, S. R. Forrest, “Non-destructive wafer recycling for low-cost thin-film flexible optoelectronics”, Adv. Funct. Mater., 24, 4284–5291 (2014).
[17] S. Moon, K. Kim, Y. Kim, J. Heo, J. Lee, “Highly efficient single-junction GaAs thin-film solar cell on flexible substrate”, Scientific Reports., 6, 30107 (2016).
[18] H. Tributsch, “Reaction of excited chlorophyll molecules at electrodes and in photosynthesis”, ‎Photochem. Photobiol., 16, 261–9 (2008).
[19] B. O'regan, M. Grätzel, “A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films”, Nature, 353, 737 (1991).
[20] J. Gong, J. Liang, K. Sumathy, “Review on dye-sensitized solar cells (DSSCs): fundamental concepts and novel materials Renew Sustain Energy” Renew Sust Energ Rev., 16, 5848-5860 (2012).
[21] B. Julian, P. Norman, M. Soo-Jin, H. B. Robin, Gao. Peng, N. M. K, G. Michael, “Sequential deposition as a route to high-performance perovskite-sensitized solar cells”, Nature, 499, 316–9 (2013).
[22] J. Gong, K. Sumathy, Q. Qiao, Z. Zhou, “Review on dye-sensitized solar cells (DSSCs): Advanced techniques and research trends”, Renew Sust Energ Rev., 68, 234-246 (2017).
[23] A. Delamarre, M. Paire, J. F. Guillemoles, L. Lombez, “Quantitative lumines-cence mapping of Cu(In,Ga)Se2 thin-film solar cells”, Progress in Photovoltaics., 23, 1305–1312 (2014).
[24] A. Rogalski, K. Adamiec and J. Rutkowski, “Narrow-Gap Semiconductor Photodiodes”, SPIE Press, p.15-64 (2000).
[25] L. C. Chen, J. R. Wu, Z. L. Tseng, C. C. Chen, S. H. Chang, J. K. Huang, K. L. Lee, H. M. Cheng, “Annealing effect on (FAPbI3)1−x(MAPbBr3)x perovskite films in inverted-type perovskite solar cells”, Materials, 9, 747 (2016).
[26] F. Hao, C. C. Stoumpos, D. H. Cao, R. P. H. Chang, M. G. Kanatzidis, “Lead-free solid-state organic–inorganic halide perovskite solar cells”, Nature Photonics., 8, 489–494 (2014).
[27] N. J. Jeon, J. H. Noh, Y. C. Kim, W. S. Yang, S. Ryu, S. Seok, “Solvent engi-neering for high-performance inorganic–organic hybrid perovskite solar cells”, Nature Materials., 13, 897–903 (2014).
[28] A. Kojima, K. Teshima, Y. Shirai, T. Miyasaka, “Organometal halide perov-skites as visible-light sensitizers for photovoltaic cells”, Journal. ACS., 131, 6050–6051 (2009).
[29] J. H. Im, C. R. Lee, J. W. Lee, S. W. Parka, N. G. Park, “6.5% efficient perov-skite quantum-dot-sensitized solar cell”, Nanoscale., 3, 4088–4093 (2011).
[30] M. M. Lee, J. Teuscher, T. Miyasaka, T. N. Murakami, H. J. Snaith, “Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites”, Science, 338, 643-647 (2012).
[31] J. Burschka, N. Pellet, S. J. Moon, R. Humphry-Baker, P. Gao, M. K. Nazee-ruddin, M. Grätzel, “Sequential deposition as a route to high-performance perov-skite-sensitized solar cells”, Nature, 499, 316 (2013).
[32] C. Schinzer, “Distortion of Perovskites”, Retrieved, (2012).
[33] W. Travis, E. N. K. Glover, H. Bronstein, D. O. Scanlon and R. G. Palgrave, “On the application of the tolerance factor to inorganic and hybrid halide perov-skites: a revised system”, Chem. Sci., 7, 4548–4556 (2016).
[34] A. R. Daniel, K. Thomas, R. Uwe, J. Wiley, Sons, “Advanced characterization techniques for thin film solar cells”, 1, part II (2016).
[35] Z. Huang, D. Wang, S. Wang, T. Zhang, “Highly efficient and stable MAPbI3 perovskite solar cell induced by regulated nucleation and ostwald recrystalliza-tion”, Materials, 11, 778 (2018).
[36] F. F. Targhi, Y. S. Jalili, F. Kanjouri, “MAPbI3 and FAPbI3 perovskites as solar cells: Case study on structural, electrical and optical properties”, Results in Phys-ics, 10, 616–627 (2018).
[37] J. W. Lee, D. J. Seol, A. N. Cho, N. G. Park, “High-efficiency perovskite solar cells based on the black polymorph of HC(NH2)2PbI3”, Adv. Mater., 26, 4991–4998 (2014).
[38] M. T. Weller, O. J. Weber, J. M. Frost, A. Walsh, “Cubic perovskite structure of black formamidinium lead iodide, α‑[HC(NH2)2]PbI3, at 298 K”, J. Phys. Chem. Lett., 6, 3209−3212 (2015).
[39] W. Rehman, R. L. Milot, G. E. Eperon, C. Wehrenfennig, J. L. Boland, H. J. Snaith, M. B. Johnston, L. M. Herz, “Charge-carrier dynamics and mobilities in formamidinium lead mixed-halide perovskites”, Adv. Mater., 27, 7938−7944 (2015).
[40] F. C. Hanusch, E. Wiesenmayer, E. Mankel, A. Binek, P. Angloher, C. Fraunho-fer, N. Giesbrecht, J. M. Feckl, W. Jaegermann, D. Johrendt, T. Bein, P. Docampo, “Efficient planar heterojunction perovskite solar cells based on formamidinium lead bromide”, J. Phys. Chem. Lett., 5, 2791−2795 (2014).
[41] W. S. Yang, J. H. Noh, N. J. Jeon, Y. C. Kim, S. Ryu, J. Seo, S. II Seok, “High-performance photovoltaic perovskite layers fabricated through intramolec-ular exchange”, Science, 348, 1234-1237 (2015).
[42] A. Binek, F. C. Hanusch, P. Docampo, T. Bein, “Stabilization of the trigonal high-temperature phase of formamidinium lead iodide”, J. Phys. Chem. Lett., 6, 1249−1253 (2015).
[43] Q. Fu, X. Tang, B. Huang, T. Hu, L. Tan, L. Chen, Y. Chen, “Recent progress on the long-term stability of perovskite solar cells”, Adv. Sci., 5, 1700387 (2018).
[44] X. Sisi, F. Zhongheng, L. Weiping, W. Ya, L. Jiaming, L. Huicong, Z. Liqun, Z. Ruifeng, C. Haining, “Highly air-stable carbon-based α‑CsPbI3 perovskite solar cells with a broadened optical spectrum”, ACS Energy Lett., 3, 1824− 1831 (2018). [45] Z. Li, M. Yang, J. S. Park, S. H. Wei, J. J. Berry, K. Zhu, “Stabilizing perovskite structures by tuning tolerance factor: formation of formamidinium and cesium lead iodide solid-state alloys”, Chem. Mater., 28, 284−292 (2016).
[46] H. Choi, J. Jeong, H. B. Kim, S. Kim, B. Walker, G. H. Kim, J. Y. Kim, “Ce-sium-doped methylammonium lead iodide perovskite light absorber for hybrid solar cells”, Nano Energy, 7, 80–85 (2014).
[47] X. Xiang, W. Wenyi, L. Hongcui, Z. Bo, X. Yebin, X. Jing, Z. Dawei, G. Chun-xiao, L. Xizhe, “Spray reaction prepared FA1-xCsxPbI3 solid solution as a light har-vester for perovskite solar cells with improved humidity stability”, RSC Adv., 6, 14792–14798 (2016).
[48] M. Saliba, T. Matsui, J. Y. Seo, K. Domanski, J. P. Correa-Baena, M. K. Nazee-ruddin, S. M. Zakeeruddin, W. Tress, A. Abate, A. Hagfeldt, M. Grätzel, “Ce-sium-containing triple cation perovskite solar cells: improved stability, reproduci-bility and high efficiency”, Energy Environ. Sci., 9, 1989-1997 (2016).
[49] T. Yokoyama, D. H. Cao, C. C. Stoumpos, T. B. Song, Y. Sato, S. Aramaki, M. G. Kanatzidis, “Overcoming short-circuit in lead-free CH3NH3SnI3 perovskite solar cells via kinetically controlled gas−solid reaction film fabrication process”, J. Phys. Chem. Lett., 7, 776−782 (2016).
[50] H. Hoshi, N. Shigeeda, T. Dai, “Improved oxidation stability of tin iodide cu-bic perovskite treated by 5-ammonium valeric acid iodide”, Materials Letters, 183, 391–393 (2016).
[51] T. M. Koh, T. Krishnamoorthy, N. Yantara, C. Shi, W. L. Leong, P. P. Boix, A. C. Grimsdale, S. G. Mhaisalkar, N. Mathews, “Formamidinium tin-based perovskite with low Eg for photovoltaic applications”, J. Mater. Chem. A, 3, 14996–15000 (2015).
[52] S. Yang, W. Fu, Z. Zhang, H. Chen, C. Z. Li, “Recent advances in perovskite solar cells: efficiency, stability and lead-free perovskite”, J. Mater. Chem. A, 5, 11462–11482 (2017).
[53] X. Zhang, G. Wu, Z. Gu, B. Guo, W. Liu, S. Yang, T. Ye, C. Chen, W. Tu, H. Chen, “Active-layer evolution and efficiency improvement of (CH3NH3)3Bi2I9-based so-lar cell on TiO2-deposited ITO substrate”, Nano Res., 9, 2921–2930 (2016).
[54] P. Zhang, J. Yangab, S. -H. Wei, “Manipulation of cation combinations and configurations of halide double perovskites for solar cell absorbers”, J. Mater. Chem. A, 6, 1809–1815 (2018).
[55] W. Meng, S. Jun-jie, Z. Min, C. Yu-lang, G. Wen-hui, Z. Yao-hui, “Promising photovoltaic and solid-state-lighting materials: two-dimensional Ruddlesden–Popper type lead-free halide double perovskites Csn+1Inn/2Sbn/2I3n+1 (n = 3) and Csn+1Inn/2Sbn/2- Cl3n+1/Csm+1Cum/2Bim/2Cl3m+1 (n = 3, m = 1)”, J. Mater. Chem. C, 6, 11575-11586 (2018).
[56] S. D. Stranks, G. E. Eperon, G. Grancini, C. Menelaou, M. J. P. Alcocer, T. Leijtens, L. M. Herz, A. Petrozza, H. J. Snaith, “Electron-hole diffusion lengths ex-ceeding 1 micrometer in an organometal trihalide perovskite absorber”, Science, 342, 341−344 (2013).
[57] C. Li, J. Wei, M. Sato, H. Koike, Z. Xie, Y. Q. Li, K. Kanai, S. Kera, N. Ueno, J. X. Tang, “Halide-substituted electronic properties of organometal halide perov-skite films: direct and inverse photoemission studies”, ACS Appl. Mater. Interfaces, 8, 11526−11531 (2016).
[58] T. J. Jacobsson, J. P. Correa-Baena, M. Pazoki, M. Saliba, K. Schenk, M. Grät-zelc, A. Hagfeldt, “Exploration of the compositional space for mixed lead halogen perovskites for high efficiency solar cells”, Energy Environ. Sci., 9, 1706-1724 (2016).
[59] J. H. Noh, S. H. Im, J. H. Heo, T. N. Mandal, S. II Seok, “Chemical management for colorful, efficient, and stable inorganic-organic hybrid nanostructured solar cells”, Nano Lett., 13, 1764−1769 (2013).
[60] K. O. Luis, J. J. P. Emilio, Q. Yabing, “Progress on perovskite materials and solar cells with mixed cations and halide anions”, ACS Appl. Mater. Interfaces, 9, 30197−30246 (2017).
[61] S. Yang, W. Liu, L. Zuo, X. Zhang, T. Ye, J. Chen, C. Z. Li, G. Wu, H. Chen, “Thiocyanate assisted performance enhancement of formamidinium based planar perovskite solar cells through a single one-step solution process”, J. Mater. Chem. A, 4, 9430–9436 (2016).
[62] Y. Cai, S. Wang, M. Sun, X. Li, Y. Xiao, “Mixed cations and mixed halide per-ovskite solar cell with lead thiocyanate additive for high efficiency and long-term moisture stability”, Organic Electronics, 53, 249–255 (2018).
[63] Y. Yu, C. Wang, C. R. Grice, N. Shrestha, J. Chen, D. Zhao, W. Liao, A. J. Ci-maroli, P. J. Roland, R. J. Ellingson, Y. Yan, “Improvingthe performance of forma-midinium and cesium lead triiodide perovskite solar cells using lead thiocyanate additives”, Chem Sus Chem., 9, 3288–3297 (2016).
[64] I. C. Smith, E. T. Hoke, D. Solis-Ibarra, M. D. McGehee, H. I. Karunadasa, “A layered hybrid perovskite solar-cell absorber with enhanced moisture stability”, Angew. Chem., 126, 11414 (2014).
[65] L. N. Quan, M. Yuan, R. Comin, O. Voznyy, E. M. Beauregard, S. Hoogland, A. Buin, A. R. Kirmani, K. Zhao, A. Amassian, D. H. Kim, E. H. Sargent, “lig-and-stabilized reduced-dimensionality perovskites”, J. Am. Chem. Soc., 138, 2649 (2016).
[66] A. Krishna, S. Gottis, M. K. Nazeeruddin, F. Sauvage, “Mixed dimensional 2D/3D hybrid perovskite absorbers: The future of perovskite solar cells”, Adv. Funct. Mater., 29, 1806482 (2019).
[67] A. Z. Chen, M. Shiu, J. H. Ma, M. R. Alpert, D. Zhang, B. J. Foley, D. M. Smilg-ies, S. H. Lee, J. J. Choi, “Origin of vertical orientation in two-dimensional metal halide perovskites and its effect on photovoltaic performance”, ‎Nat. Commun., 9, (2018).
[68] G. Liu, H. Zheng, X. Xu, L. Z. Zhu, X. Zhang, X. Pan, “Design of high-efficiency and environmentally stable mixed dimensional perovskite solar cells based on cesium formamidinium lead halide component”, Chem. Mater., 30, 7691−7698 (2018).
[69] Y. Zou, Y. Cui, H. Y. Wang, Q. Cai, C. Mu, J. P. Zhang, “Highly efficient and stable 2D–3D perovskite solar cells fabricated by interfacial modification”, Nan-otechnology, 30, 275202 (2019).
[70] H. S. Yoo, N. G. Park, “Post-treatment of perovskitefilm with phenyl-alkylammonium iodide for hysteresis-less perovskite solar cells”, Sol Energy Ma-ter Sol Cells., 179, 57–65 (2018).
[71] W. Peng, J. Yin, K. T. Ho, O. Ouellette, M. D. Bastiani, B. Murali, O. E. Tall, C. Shen, X. Miao, J. Pan, E. Alarousu, J. -H. He, B. S. Ooi, O. F. Mohammed, E. Sargent, O. M. Bakr, “Ultralow self-doping in two-dimensional hybrid perovskite single crystals”, Nano Lett., 17, 4759−4767 (2017).
[72] X. Zheng, C. Wu, S. K. Jha, Z. Li, K. Zhu, S. Priya, “Improved phase stability of formamidinium lead triiodide perovskite by strain relaxation”, ACS Energy Lett., 1, 1014-1020 (2016).
[73] J. F. Liao, H. S. Rao, B. X. Chen, D. B. Kuang, C. Y. Su, “Dimension engineer-ing on cesium lead iodide for efficient and stable perovskite solar cells”, : J. Mater. Chem. A, 5, 2066 (2017).
[74] A. A. Zhumekenov, M. I. Saidaminov, M. A. Haque, E. Alarousu, S. P. Sarmah, B. Murali, I. Dursun, X. H. Miao, A. L. Abdelhady, T. Wu, O. F. Mohammed, O. M. Bakr, “Formamidinium lead halide perovskite crystals with unprecedented long carrier dynamics and diffusion length”, ACS Energy Lett., 1, 32−37 (2016).
[75] Y. H. Chang, J. C. Lin, Y. C. Chen, T. R. Kuo, D. Y. Wang, “Facile synthesis of two-dimensional Ruddlesden–Popper perovskite quantum dots with fine-tunable optical properties”, Nanoscale Res Lett., 13, 247 (2018).
[76] I. Spanopoulos, I. Hadar, W. Ke, Q. Tu, M. Chen, H. Tsai, Y. He, G. Shekhawat, V. P. Dravid, M. R. Wasielewski, A. D. Mohite, C. C. Stoumpos, M. G. Kanatzidis, “Uniaxial expansion of the 2D Ruddlesden−Popper perovskite family for im-proved environmental stability”, J. Am. Chem. Soc., 141, 5518−5534 (2019).
[77] J. M. Zhanga, F. Maa, K. W. Xu, “Calculation of the surface energy of FCC metals with modified embedded-atom method”, Appl Surf Sci., 229, 34–42 (2004).
[78] S. G. Wang, E. K. Tian, C. W. Lung, “Surface energy of arbitrary crystal plane of bcc and fcc metals”, J. Phys. Chem. Solids, 61, 1295–1300 (2000).
[79] Z. L. Wang, Z.C. Kang, “Perovskite and Related Structure Systems. In: Func-tional and Smart Materials”, Springer, Boston, MA (1998).
[80] https://www.renishaw.com.cn/zh/photoluminescence-explained--25809
[81] https://ap.nuk.edu.tw/m/412-1000-130.php?Lang=zh-tw
[82] http://www.sohu.com/a/126593825_119960
[83] http://www.shoif.com/old_version/x-光绕射与布拉格定律.shtml
[84] https://www.toyo.co.jp/microscopy/casestudy/detail/id=5474
[85] http://www.amtech.com.tw/custom_61209.html
[86] X. Zeng, Z. H. Yang, X. H. Zhang, “Characterization tools for polymer thin films”, Acta Phys. Sin., 65, 176801 (2016).
[87] W. Melitz, J. Shen, A. C. Kummel, S. Lee, “Kelvin probe force microscopy and its application”, Surf Sci Rep., 66, 1–27 (2011).
[88] D. G. Billing, A. Lemmerer, “Synthesis, characterization and phase transitions in the inorganic–organic layered perovskite-type hybrids [(CnH2n + 1NH3)2PbI4], n = 4, 5 and 6”, Acta Cryst., 63, 735–747 (2007).
[89] G. Grancini, M. K. Nazeeruddin, “Dimensional tailoring of hybrid perovskites for photovoltaics”, Nat Rev Mater., 4, 4-22 (2019).