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研究生： 林韋任
Wei-Jen Lin
論文名稱： A First-Principle Study of the Thermal Degradation Mechanisms of CH3NH3PbI3 Perovskite
指導教授： 蔡惠旭
Hui-Hsu Gavin Tsai
口試委員:
學位類別： 碩士
Master
系所名稱： 理學院 - 化學學系
Department of Chemistry
論文出版年： 2018
畢業學年度： 106
語文別： 英文
論文頁數： 39
中文關鍵詞： 鈣鈦礦太陽能電池 、熱分解 、理論計算
外文關鍵詞： Perovskite solar cells, Thermal degradation, First-principle calculation
相關次數： 點閱：11  下載：0 
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    • 近幾年鈣鈦礦材料的高能量轉換效率引起許多研究者關注的吸光材料，而methylammonium lead iodide (CH3NH3PbI3, MAPbI3) 被認為是極具潛力的鈣鈦礦材料之ㄧ，然而其化學不穩定性是將該材料應用於太陽能電池上所必須面臨的一大挑戰。近來有許多針對熱穩定性研究的文獻提供了兩個可能的熱分解反應，兩個分解反應之間的差異就在於與碘離子反應的對象，碘離子和CH3NH3+中N上的H反應生成HI及CH3NH2，而跟C反應則得到的產物則為CH3I以及NH3。本研究利用密度泛函理論 (Density Functional Theory, DFT) 計算MAPbI3兩種熱分解反應過程中構型以及位能的變化。我們建立了兩套計算模型試圖模擬實際熱分解過程，分別為自由氣體模型以及晶格表面模型，在自由氣體模型中生成CH3I以及NH3所需的活化能較生成HI及CH3NH2低，然而由於初始結構透過Boltzmann distribution的計算發現在氣態狀態下碘離子是無法跟C反應的。透過晶格表面的模型計算得到的活化能結果與氣態模型類似，且碘離子與C或N上的H反應的分布是接近，依此結果推論出熱分解的主要產物應為CH3I以及NH3。本研究的結果希望能夠提供相關研究者一些線索去設計具有良好熱穩定性的鈣鈦礦太陽能電池。

    The poor stability of organometallic halide perovskite, especially the CH3NH3PbI3 (MAPbI3), in high temperature environment (up to 85 ºC) is one of the challenge problems retarding for its wide applications. The thermal degradation mechanism of CH3NH3PbI3 perovskite remains unclear. In this study, we employ firstprinciple density functional theory to investigate the energetic and structural mechanisms of the thermal degradation of CH3NH3PbI3 perovskite. We focus on studying the two reaction pathways of iodine with the CH3NH3+: one reaction is the proton abstraction reaction from methylammonium to iodine and the products are hydrogen iodide (HI) and methylamine (CH3NH2). The other reaction is a SN2 substituent reaction using the iodine as the nucleophile to attack the carbon atom of CH3NH3+ to yield the products of iodomethane (CH3I) and ammonia (NH3). The crystal structures of CH3NH3PbI3 perovskite with PbI2-terminated and MAI-terminated surfaces are employed in this study. Our calculations suggest that the SN2 substituent reaction requires lower activation energy than the proton abstraction reaction. Namely, the main products of the thermal detraction of CH3NH3PbI3 perovskite are CH3I, NH3, and PbI2. Our study gives clues to rationally design of the thermally stable organic cations. To verify the overall mechanism, we will scan the 2D energy profiles to make sure that PbI2 generates in our future work.

    摘要 I Abstract II 致謝 III Contents IV List of Figures V Chapter 1 - Introduction 1 Chapter 2 - Computational Methods 5 Chapter 3 - Result and Discussion 7 3.1 Chemical Reaction Pathway P1 of I-MA, PbI3-MA, and Pb2I5-MA Reactions 11 3.2 Reaction Pathway P2 of I-MA, PbI3-MA, and Pb2I5-MA Reactions 16 3.3 Reaction Pathway P1 of PbI2-term Reaction 21 3.4 Reaction Pathway P2 of PbI2-term Reaction 23 3.5 Reaction Pathway P1 of MAI-term Reaction 25 3.6 Reaction Pathway P2 of MAI-term Reaction 27 Chapter 4 - Conclusion 29 References 30

    1. Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T., Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131 (17), 6050-+.
    2. Green, M. A.; Hishikawa, Y.; Dunlop, E. D.; Levi, D. H.; Hohl-Ebinger, J.; Ho-Baillie, A. W. Y., Solar cell efficiency tables (version 52). Prog. Photovoltaics 2018, 26 (7), 427-436.
    3. Haruyama, J.; Sodeyama, K.; Han, L.; Tateyama, Y., Surface Properties of CH3NH3PbI3 for Perovskite Solar Cells. Accounts of Chemical Research 2016, 49 (3), 554-561.
    4. Ponseca, C. S.; Savenije, T. J.; Abdellah, M.; Zheng, K. B.; Yartsev, A.; Pascher, T.; Harlang, T.; Chabera, P.; Pullerits, T.; Stepanov, A.; Wolf, J. P.; Sundstrom, V., Organometal Halide Perovskite Solar Cell Materials Rationalized: Ultrafast Charge Generation, High and Microsecond-Long Balanced Mobilities, and Slow Recombination. J. Am. Chem. Soc. 2014, 136 (14), 5189-5192.
    5. Stoumpos, C. C.; Malliakas, C. D.; Kanatzidis, M. G., Semiconducting Tin and Lead Iodide Perovskites with Organic Cations: Phase Transitions, High Mobilities, and Near-Infrared Photoluminescent Properties. Inorganic Chemistry 2013, 52 (15), 9019-9038.
    6. Wehrenfennig, C.; Eperon, G. E.; Johnston, M. B.; Snaith, H. J.; Herz, L. M., High Charge Carrier Mobilities and Lifetimes in Organolead Trihalide Perovskites. Advanced Materials 2014, 26 (10), 1584-1589.
    7. Xing, G. C.; Mathews, N.; Sun, S. Y.; Lim, S. S.; Lam, Y. M.; Gratzel, M.; Mhaisalkar, S.; Sum, T. C., Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH3NH3PbI3. Science 2013, 342 (6156), 344-347.
    8. Boix, P. P.; Nonomura, K.; Mathews, N.; Mhaisalkar, S. G., Current progress and future perspectives for organic/inorganic perovskite solar cells. Materials Today 2014, 17 (1), 16-23.
    9. Heo, J. H.; Song, D. H.; Patil, B. R.; Im, S. H., Recent Progress of Innovative Perovskite Hybrid Solar Cells. Israel Journal of Chemistry 2015, 55 (9), 966-977.
    10. Niu, G. D.; Guo, X. D.; Wang, L. D., Review of recent progress in chemical stability of perovskite solar cells. J. Mater. Chem. A 2015, 3 (17), 8970-8980.
    11. Wang, Z.; Shi, Z. J.; Li, T. T.; Chen, Y. H.; Huang, W., Stability of Perovskite Solar Cells: A Prospective on the Substitution of the A Cation and X Anion. Angewandte Chemie-International Edition 2017, 56 (5), 1190-1212.
    12. Han, Y.; Meyer, S.; Dkhissi, Y.; Weber, K.; Pringle, J. M.; Bach, U.; Spiccia, L.; Cheng, Y. B., Degradation observations of encapsulated planar CH3NH3PbI3 perovskite solar cells at high temperatures and humidity. J. Mater. Chem. A 2015, 3 (15), 8139-8147.
    13. Conings, B.; Drijkoningen, J.; Gauquelin, N.; Babayigit, A.; D'Haen, J.; D'Olieslaeger, L.; Ethirajan, A.; Verbeeck, J.; Manca, J.; Mosconi, E.; De Angelis, F.; Boyen, H. G., Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite. Advanced Energy Materials 2015, 5 (15).
    14. Pisoni, A.; Jacimovic, J.; Barisic, O. S.; Spina, M.; Gaal, R.; Forro, L.; Horvath, E., Ultra-Low Thermal Conductivity in Organic-Inorganic Hybrid Perovskite CH3NH3PbI3. J. Phys. Chem. Lett. 2014, 5 (14), 2488-2492.
    15. Dualeh, A.; Gao, P.; Seok, S. I.; Nazeeruddin, M. K.; Graetzel, M., Thermal Behavior of Methylammonium Lead-Trihalide Perovskite Photovoltaic Light Harvesters. Chem. Mat. 2014, 26 (21), 6160-6164.
    16. Yang, J. L.; Siempelkamp, B. D.; Liu, D. Y.; Kelly, T. L., Investigation of CH3NH3PbI3 Degradation Rates and Mechanisms in Controlled Humidity Environments Using in Situ Techniques. Acs Nano 2015, 9 (2), 1955-1963.
    17. Philippe, B.; Park, B. W.; Lindblad, R.; Oscarsson, J.; Ahmadi, S.; Johansson, E. M. J.; Rensmo, H., Chemical and Electronic Structure Characterization of Lead Halide Perovskites and Stability Behavior under Different Exposures-A Photoelectron Spectroscopy Investigation. Chem. Mat. 2015, 27 (5), 1720-1731.
    18. Manser, J. S.; Saidaminov, M. I.; Christians, J. A.; Bakr, O. M.; Kamat, P. V., Making and Breaking of Lead Halide Perovskites. Accounts of Chemical Research 2016, 49 (2), 330-338.
    19. Shirayama, M.; Kato, M.; Miyadera, T.; Sugita, T.; Fujiseki, T.; Hara, S.; Kadowaki, H.; Murata, D.; Chikamatsu, M.; Fujiwara, H., Degradation mechanism of CH3NH3PbI3 perovskite materials upon exposure to humid air. Journal of Applied Physics 2016, 119 (11).
    20. Juarez-Perez, E. J.; Hawash, Z.; Raga, S. R.; Ono, L. K.; Qi, Y. B., Thermal degradation of CH3NH3PbI3 perovskite into NH3 and CH3I gases observed by coupled thermogravimetry-mass spectrometry analysis. Energy Environ. Sci. 2016, 9 (11), 3406-3410.
    21. Nenon, D. P.; Christians, J. A.; Wheeler, L. M.; Blackburn, J. L.; Sanehira, E. M.; Dou, B. J.; Olsen, M. L.; Zhu, K.; Berrya, J. J.; Luther, J. M., Structural and chemical evolution of methylammonium lead halide perovskites during thermal processing from solution. Energy Environ. Sci. 2016, 9 (6), 2072-2082.
    22. Haruyama, J.; Sodeyama, K.; Han, L. Y.; Tateyama, Y., Termination Dependence of Tetragonal CH3NH3PbI3 Surfaces for Perovskite Solar Cells. J. Phys. Chem. Lett. 2014, 5 (16), 2903-2909.
    23. Wang, Y.; Sumpter, B. G.; Huang, J. S.; Zhang, H. M.; Liu, P. R.; Yang, H. G.; Zhao, H. J., Density Functional Studies of Stoichiometric Surfaces of Orthorhombic Hybrid Perovskite CH3NH3PbI3. Journal of Physical Chemistry C 2015, 119 (2), 1136-1145.
    24. Perdew, J. P.; Burke, K.; Ernzerhof, M., Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77 (18), 3865-3868.
    25. Delley, B., An All-Electron Numerical-Method for Solving the Local Density Functional for Polyatomic-Molecules. Journal of Chemical Physics 1990, 92 (1), 508-517.
    26. Delley, B., From molecules to solids with the DMol(3) approach. Journal of Chemical Physics 2000, 113 (18), 7756-7764.
    27. Tkatchenko, A.; Scheffler, M., Accurate Molecular van der Waals Interactions from Ground-State Electron Density and Free-Atom Reference Data. Phys. Rev. Lett. 2009, 102 (7), 4.
    28. Ren, Y. X.; Oswald, I. W. H.; Wang, X. P.; McCandless, G. T.; Chan, J. Y., Orientation of Organic Cations in Hybrid Inorganic-Organic Perovskite CH3NH3PbI3 from Subatomic Resolution Single Crystal Neutron Diffraction Structural Studies. Crystal Growth & Design 2016, 16 (5), 2945-2951.
    29. Motta, C.; El-Mellouhi, F.; Kais, S.; Tabet, N.; Alharbi, F.; Sanvito, S., Revealing the role of organic cations in hybrid halide perovskite CH3NH3PbI3. Nat. Commun. 2015, 6, 7.
    30. Monkhorst, H. J.; Pack, J. D., Special points for Brillouin-zone integrations. Physical Review B 1976, 13 (12), 5188-5192.

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