Incorporating Large A Cations into Lead Iodide Perovskite Cages: Relaxed Goldschmidt Tolerance Factor and Impact on Exciton–Phonon Interaction

Fu, Yongping; Hautzinger, Matthew P.; Luo, Ziyu; Wang, Feifan; Pan, Dongxu; Aristov, Michael M.; Guzei, Ilia A.; Pan, Anlian; Zhu, Xiaoyang; Jin, Song

doi:10.1021/acscentsci.9b00367

Title: Incorporating Large A Cations into Lead Iodide Perovskite Cages: Relaxed Goldschmidt Tolerance Factor and Impact on Exciton–Phonon Interaction

Journal Article · Wed Jul 24 00:00:00 EDT 2019 · ACS Central Science

DOI:https://doi.org/10.1021/acscentsci.9b00367· OSTI ID:1544598

Fu, Yongping ^[1];

^[1]; Luo, Ziyu ^[2];

^[3]; Pan, Dongxu ^[1]; Aristov, Michael M. ^[1];

^[1];

^[2];

^[3];

^[1]

Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, Hunan University, Changsha 410082, P. R. China
Department of Chemistry, Columbia University, New York, New York 10027, United States

The stability and formation of a perovskite structure is dictated by the Goldschmidt tolerance factor as a general geometric guideline. The tolerance factor has limited the choice of cations (A) in 3D lead iodide perovskites (APbI₃), an intriguing class of semiconductors for high-performance photovoltaics and optoelectronics. Here, we show the tolerance factor requirement is relaxed in 2D Ruddlesden-Popper (RP) perovskites, enabling the incorporation of a variety of larger cations beyond the methylammonium (MA), formamidinium, and cesium ions in the lead iodide perovskite cages for the first time. This is unequivocally confirmed with the single-crystal X-ray structure of newly synthesized guanidinium (GA)-based ($$n$$-C₆H₁₃NH₃)₂(GA)Pb₂I₇, which exhibits significantly enlarged and distorted perovskite cage containing sterically constrained GA cation. Structural comparison with ($$n$$-C₆H₁₃NH₃)₂(MA)Pb₂I₇ reveals that the structural stabilization originates from the mitigation of strain accumulation and self-adjustable strain-balancing in 2D RP structures. Furthermore, spectroscopic studies show a large A cation significantly influences carrier dynamics and exciton-phonon interactions through modulating the inorganic sublattice. These results enrich the diverse families of perovskite materials, provide new insights into the mechanistic role of A-site cations on their physical properties, and have implications to solar device studies using engineered perovskite thin films incorporating such large organic cations.

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Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

Grant/Contract Number:: FG02-09ER46664; SC0010692

OSTI ID:: 1544598

Alternate ID(s):: OSTI ID: 1559863

Journal Information:: ACS Central Science, Journal Name: ACS Central Science Vol. 5 Journal Issue: 8; ISSN 2374-7943

Publisher:: American Chemical SocietyCopyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 95 works

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References (73)

Local Polar Fluctuations in Lead Halide Perovskite Crystals Yaffe, Omer; Guo, Yinsheng; Tan, Liang Z. Physical Review Letters, Vol. 118, Issue 13 https://doi.org/10.1103/PhysRevLett.118.136001	journal	March 2017
Extrinsic and Dynamic Edge States of Two-Dimensional Lead Halide Perovskites Shi, Enzheng; Deng, Shibin; Yuan, Biao ACS Nano https://doi.org/10.1021/acsnano.8b07631	journal	February 2019
Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells Wang, Nana; Cheng, Lu; Ge, Rui Nature Photonics, Vol. 10, Issue 11 https://doi.org/10.1038/nphoton.2016.185	journal	September 2016
Dynamic disorder, phonon lifetimes, and the assignment of modes to the vibrational spectra of methylammonium lead halide perovskites Leguy, Aurélien M. A.; Goñi, Alejandro R.; Frost, Jarvist M. Physical Chemistry Chemical Physics, Vol. 18, Issue 39 https://doi.org/10.1039/C6CP03474H	journal	January 2016
Ultralow Self-Doping in Two-dimensional Hybrid Perovskite Single Crystals Peng, Wei; Yin, Jun; Ho, Kang-Ting Nano Letters, Vol. 17, Issue 8 https://doi.org/10.1021/acs.nanolett.7b01475	journal	June 2017
How Lattice Dynamics Moderate the Electronic Properties of Metal-Halide Perovskites Herz, Laura M. The Journal of Physical Chemistry Letters, Vol. 9, Issue 23 https://doi.org/10.1021/acs.jpclett.8b02811	journal	November 2018
Probing femtosecond lattice displacement upon photo-carrier generation in lead halide perovskite Batignani, Giovanni; Fumero, Giuseppe; Srimath Kandada, Ajay Ram Nature Communications, Vol. 9, Issue 1 https://doi.org/10.1038/s41467-018-04367-6	journal	May 2018
Suppressed Ion Migration along the In-Plane Direction in Layered Perovskites Xiao, Xun; Dai, Jun; Fang, Yanjun ACS Energy Letters, Vol. 3, Issue 3 https://doi.org/10.1021/acsenergylett.8b00047	journal	February 2018
Selective Stabilization and Photophysical Properties of Metastable Perovskite Polymorphs of CsPbI ₃ in Thin Films Fu, Yongping; Rea, Morgan T.; Chen, Jie Chemistry of Materials, Vol. 29, Issue 19 https://doi.org/10.1021/acs.chemmater.7b02948	journal	September 2017
Real-Time Observation of Exciton–Phonon Coupling Dynamics in Self-Assembled Hybrid Perovskite Quantum Wells Ni, Limeng; Huynh, Uyen; Cheminal, Alexandre ACS Nano, Vol. 11, Issue 11 https://doi.org/10.1021/acsnano.7b03984	journal	October 2017
Formation of Stable Mixed Guanidinium–Methylammonium Phases with Exceptionally Long Carrier Lifetimes for High-Efficiency Lead Iodide-Based Perovskite Photovoltaics Kubicki, Dominik J.; Prochowicz, Daniel; Hofstetter, Albert Journal of the American Chemical Society, Vol. 140, Issue 9 https://doi.org/10.1021/jacs.7b12860	journal	February 2018
Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells Kojima, Akihiro; Teshima, Kenjiro; Shirai, Yasuo Journal of the American Chemical Society, Vol. 131, Issue 17, p. 6050-6051 https://doi.org/10.1021/ja809598r	journal	May 2009
Two-Dimensional Hybrid Halide Perovskites: Principles and Promises Mao, Lingling; Stoumpos, Constantinos C.; Kanatzidis, Mercouri G. Journal of the American Chemical Society, Vol. 141, Issue 3 https://doi.org/10.1021/jacs.8b10851	journal	November 2018
Giant Rashba splitting in 2D organic-inorganic halide perovskites measured by transient spectroscopies Zhai, Yaxin; Baniya, Sangita; Zhang, Chuang Science Advances, Vol. 3, Issue 7 https://doi.org/10.1126/sciadv.1700704	journal	July 2017
Organic–Inorganic Perovskites: Structural Versatility for Functional Materials Design Saparov, Bayrammurad; Mitzi, David B. Chemical Reviews, Vol. 116, Issue 7 https://doi.org/10.1021/acs.chemrev.5b00715	journal	March 2016
Large guanidinium cation mixed with methylammonium in lead iodide perovskites for 19% efficient solar cells Jodlowski, Alexander D.; Roldán-Carmona, Cristina; Grancini, Giulia Nature Energy, Vol. 2, Issue 12 https://doi.org/10.1038/s41560-017-0054-3	journal	December 2017
Metal halide perovskite nanostructures for optoelectronic applications and the study of physical properties Fu, Yongping; Zhu, Haiming; Chen, Jie Nature Reviews Materials, Vol. 4, Issue 3 https://doi.org/10.1038/s41578-019-0080-9	journal	February 2019
Myths and reality of HPbI3 in halide perovskite solar cells Ke, Weijun; Spanopoulos, Ioannis; Stoumpos, Constantinos C. Nature Communications, Vol. 9, Issue 1 https://doi.org/10.1038/s41467-018-07204-y	journal	November 2018
Entropy in halide perovskites Katan, Claudine; Mohite, Aditya D.; Even, Jacky Nature Materials, Vol. 17, Issue 5 https://doi.org/10.1038/s41563-018-0070-0	journal	April 2018
Revealing the role of organic cations in hybrid halide perovskite CH3NH3PbI3 Motta, Carlo; El-Mellouhi, Fedwa; Kais, Sabre Nature Communications, Vol. 6, Issue 1 https://doi.org/10.1038/ncomms8026	journal	April 2015
Ruddlesden–Popper Hybrid Lead Iodide Perovskite 2D Homologous Semiconductors Stoumpos, Constantinos C.; Cao, Duyen H.; Clark, Daniel J. Chemistry of Materials, Vol. 28, Issue 8, p. 2852-2867 https://doi.org/10.1021/acs.chemmater.6b00847	journal	April 2016
Carrier lifetimes of >1 μs in Sn-Pb perovskites enable efficient all-perovskite tandem solar cells Tong, Jinhui; Song, Zhaoning; Kim, Dong Hoe Science, Vol. 364, Issue 6439 https://doi.org/10.1126/science.aav7911	journal	April 2019
Rotational Cation Dynamics in Metal Halide Perovskites: Effect on Phonons and Material Properties Gallop, Nathaniel P.; Selig, Oleg; Giubertoni, Giulia The Journal of Physical Chemistry Letters, Vol. 9, Issue 20 https://doi.org/10.1021/acs.jpclett.8b02227	journal	September 2018
Optical phonons in methylammonium lead halide perovskites and implications for charge transport Sendner, Michael; Nayak, Pabitra K.; Egger, David A. Materials Horizons, Vol. 3, Issue 6 https://doi.org/10.1039/C6MH00275G	journal	January 2016
Lead halide perovskites: Crystal-liquid duality, phonon glass electron crystals, and large polaron formation Miyata, Kiyoshi; Atallah, Timothy L.; Zhu, X. -Y. Science Advances, Vol. 3, Issue 10 https://doi.org/10.1126/sciadv.1701469	journal	October 2017
Acoustic-optical phonon up-conversion and hot-phonon bottleneck in lead-halide perovskites Yang, Jianfeng; Wen, Xiaoming; Xia, Hongze Nature Communications, Vol. 8, Issue 1 https://doi.org/10.1038/ncomms14120	journal	January 2017
Highly Tunable Colloidal Perovskite Nanoplatelets through Variable Cation, Metal, and Halide Composition Weidman, Mark C.; Seitz, Michael; Stranks, Samuel D. ACS Nano, Vol. 10, Issue 8 https://doi.org/10.1021/acsnano.6b03496	journal	July 2016
What Remains Unexplained about the Properties of Halide Perovskites? Egger, David A.; Bera, Achintya; Cahen, David Advanced Materials, Vol. 30, Issue 20 https://doi.org/10.1002/adma.201800691	journal	March 2018
The influence of the Rashba effect Stranks, Samuel D.; Plochocka, Paulina Nature Materials, Vol. 17, Issue 5 https://doi.org/10.1038/s41563-018-0067-8	journal	April 2018
Electron–Phonon Scattering in Atomically Thin 2D Perovskites Guo, Zhi; Wu, Xiaoxi; Zhu, Tong ACS Nano, Vol. 10, Issue 11 https://doi.org/10.1021/acsnano.6b04265	journal	October 2016
Semiconducting Tin and Lead Iodide Perovskites with Organic Cations: Phase Transitions, High Mobilities, and Near-Infrared Photoluminescent Properties Stoumpos, Constantinos C.; Malliakas, Christos D.; Kanatzidis, Mercouri G. Inorganic Chemistry, Vol. 52, Issue 15, p. 9019-9038 https://doi.org/10.1021/ic401215x	journal	July 2013
Quantum dot-induced phase stabilization of -CsPbI3 perovskite for high-efficiency photovoltaics Swarnkar, A.; Marshall, A. R.; Sanehira, E. M. Science, Vol. 354, Issue 6308 https://doi.org/10.1126/science.aag2700	journal	October 2016
Investigating the Role of the Organic Cation in Formamidinium Lead Iodide Perovskite Using Ultrafast Spectroscopy Taylor, Victoria C. A.; Tiwari, Devendra; Duchi, Marta The Journal of Physical Chemistry Letters, Vol. 9, Issue 4 https://doi.org/10.1021/acs.jpclett.7b03296	journal	February 2018
Light-induced picosecond rotational disordering of the inorganic sublattice in hybrid perovskites Wu, Xiaoxi; Tan, Liang Z.; Shen, Xiaozhe Science Advances, Vol. 3, Issue 7 https://doi.org/10.1126/sciadv.1602388	journal	July 2017
Impact of Layer Thickness on the Charge Carrier and Spin Coherence Lifetime in Two-Dimensional Layered Perovskite Single Crystals Chen, Xihan; Lu, Haipeng; Li, Zhen ACS Energy Letters, Vol. 3, Issue 9 https://doi.org/10.1021/acsenergylett.8b01315	journal	August 2018
Interplay between organic cations and inorganic framework and incommensurability in hybrid lead-halide perovskite ${CH}_{3} {NH}_{3} {PbBr}_{3}$ Guo, Yinsheng; Yaffe, Omer; Paley, Daniel W. Physical Review Materials, Vol. 1, Issue 4 https://doi.org/10.1103/PhysRevMaterials.1.042401	journal	September 2017
Two-Dimensional Lead Halide Perovskites Templated by a Conjugated Asymmetric Diammonium Hautzinger, Matthew P.; Dai, Jun; Ji, Yujin Inorganic Chemistry, Vol. 56, Issue 24 https://doi.org/10.1021/acs.inorgchem.7b02285	journal	November 2017
On the application of the tolerance factor to inorganic and hybrid halide perovskites: a revised system Travis, W.; Glover, E. N. K.; Bronstein, H. Chemical Science, Vol. 7, Issue 7 https://doi.org/10.1039/C5SC04845A	journal	January 2016
Excited-state vibrational dynamics toward the polaron in methylammonium lead iodide perovskite Park, Myeongkee; Neukirch, Amanda J.; Reyes-Lillo, Sebastian E. Nature Communications, Vol. 9, Issue 1 https://doi.org/10.1038/s41467-018-04946-7	journal	June 2018
Hybrid Dion–Jacobson 2D Lead Iodide Perovskites Mao, Lingling; Ke, Weijun; Pedesseau, Laurent Journal of the American Chemical Society, Vol. 140, Issue 10 https://doi.org/10.1021/jacs.8b00542	journal	February 2018
Large polarons in lead halide perovskites Miyata, Kiyoshi; Meggiolaro, Daniele; Trinh, M. Tuan Science Advances, Vol. 3, Issue 8 https://doi.org/10.1126/sciadv.1701217	journal	August 2017
Electron–phonon interaction in efficient perovskite blue emitters Gong, Xiwen; Voznyy, Oleksandr; Jain, Ankit Nature Materials, Vol. 17, Issue 6 https://doi.org/10.1038/s41563-018-0081-x	journal	May 2018
Guanidinium: A Route to Enhanced Carrier Lifetime and Open-Circuit Voltage in Hybrid Perovskite Solar Cells De Marco, Nicholas; Zhou, Huanping; Chen, Qi Nano Letters, Vol. 16, Issue 2 https://doi.org/10.1021/acs.nanolett.5b04060	journal	January 2016
Cation Effect on Hot Carrier Cooling in Halide Perovskite Materials Madjet, Mohamed E.; Berdiyorov, Golibjon R.; El-Mellouhi, Fedwa The Journal of Physical Chemistry Letters, Vol. 8, Issue 18 https://doi.org/10.1021/acs.jpclett.7b01732	journal	September 2017
Lattice dynamics and vibrational spectra of the orthorhombic, tetragonal, and cubic phases of methylammonium lead iodide Brivio, Federico; Frost, Jarvist M.; Skelton, Jonathan M. Physical Review B, Vol. 92, Issue 14 https://doi.org/10.1103/PhysRevB.92.144308	journal	October 2015
A Layered Hybrid Perovskite Solar-Cell Absorber with Enhanced Moisture Stability Smith, Ian C.; Hoke, Eric T.; Solis-Ibarra, Diego Angewandte Chemie, Vol. 126, Issue 42 https://doi.org/10.1002/ange.201406466	journal	September 2014
Anharmonicity and Disorder in the Black Phases of Cesium Lead Iodide Used for Stable Inorganic Perovskite Solar Cells Marronnier, Arthur; Roma, Guido; Boyer-Richard, Soline ACS Nano, Vol. 12, Issue 4 https://doi.org/10.1021/acsnano.8b00267	journal	March 2018
Solid-state principles applied to organic–inorganic perovskites: new tricks for an old dog Kieslich, Gregor; Sun, Shijing; Cheetham, Anthony K. Chem. Sci., Vol. 5, Issue 12 https://doi.org/10.1039/C4SC02211D	journal	January 2014
Luminescent and Photoconductive Layered Lead Halide Perovskite Compounds Comprising Mixtures of Cesium and Guanidinium Cations Nazarenko, Olga; Kotyrba, Martin Robert; Wörle, Michael Inorganic Chemistry, Vol. 56, Issue 19 https://doi.org/10.1021/acs.inorgchem.7b01204	journal	September 2017
Structure–Band Gap Relationships in Hexagonal Polytypes and Low-Dimensional Structures of Hybrid Tin Iodide Perovskites Stoumpos, Constantinos C.; Mao, Lingling; Malliakas, Christos D. Inorganic Chemistry, Vol. 56, Issue 1 https://doi.org/10.1021/acs.inorgchem.6b02764	journal	December 2016
Tuning the Band Gap in Hybrid Tin Iodide Perovskite Semiconductors Using Structural Templating Knutson, Jeremy L.; Martin, James D.; Mitzi, David B. Inorganic Chemistry, Vol. 44, Issue 13 https://doi.org/10.1021/ic050244q	journal	June 2005
Enhanced photovoltage for inverted planar heterojunction perovskite solar cells Luo, Deying; Yang, Wenqiang; Wang, Zhiping Science, Vol. 360, Issue 6396 https://doi.org/10.1126/science.aap9282	journal	June 2018
Dynamical Origin of the Rashba Effect in Organohalide Lead Perovskites: A Key to Suppressed Carrier Recombination in Perovskite Solar Cells? Etienne, Thibaud; Mosconi, Edoardo; De Angelis, Filippo The Journal of Physical Chemistry Letters, Vol. 7, Issue 9 https://doi.org/10.1021/acs.jpclett.6b00564	journal	April 2016
Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites Lee, M. M.; Teuscher, J.; Miyasaka, T. Science, Vol. 338, Issue 6107, p. 643-647 https://doi.org/10.1126/science.1228604	journal	October 2012
Infrared-pump electronic-probe of methylammonium lead iodide reveals electronically decoupled organic and inorganic sublattices Guo, Peijun; Mannodi-Kanakkithodi, Arun; Gong, Jue Nature Communications, Vol. 10, Issue 1 https://doi.org/10.1038/s41467-019-08363-2	journal	January 2019
Stabilization of the Metastable Lead Iodide Perovskite Phase via Surface Functionalization Fu, Yongping; Wu, Tao; Wang, Jue Nano Letters, Vol. 17, Issue 7 https://doi.org/10.1021/acs.nanolett.7b01500	journal	June 2017
Universal Dynamics of Molecular Reorientation in Hybrid Lead Iodide Perovskites Fabini, Douglas H.; Siaw, Ting Ann; Stoumpos, Constantinos C. Journal of the American Chemical Society, Vol. 139, Issue 46 https://doi.org/10.1021/jacs.7b09536	journal	November 2017
Synthesis, Crystal Structures, Optical Properties, and Phase Transitions of the Layered Guanidinium-Based Hybrid Perovskites [C(NH ₂ ) ₃ ] ₂ M I ₄ ; M = Sn, Pb : Synthesis, Crystal Structures, Optical Properties, and Phase Transitions of the Layered Guanidinium-Based Hybrid Perovskites [C(NH Daub, Michael; Haber, Christoph; Hillebrecht, Harald European Journal of Inorganic Chemistry, Vol. 2017, Issue 7 https://doi.org/10.1002/ejic.201601499	journal	February 2017
High Members of the 2D Ruddlesden-Popper Halide Perovskites: Synthesis, Optical Properties, and Solar Cells of (CH 3 (CH 2 ) 3 NH 3 ) 2 (CH 3 NH 3 ) 4 Pb 5 I 16 Stoumpos, Constantinos C.; Soe, Chan Myae Myae; Tsai, Hsinhan Chem, Vol. 2, Issue 3 https://doi.org/10.1016/j.chempr.2017.02.004	journal	March 2017
Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance Saliba, M.; Matsui, T.; Domanski, K. Science, Vol. 354, Issue 6309 https://doi.org/10.1126/science.aah5557	journal	September 2016
Broad Wavelength Tunable Robust Lasing from Single-Crystal Nanowires of Cesium Lead Halide Perovskites (CsPbX ₃ , X = Cl, Br, I) Fu, Yongping; Zhu, Haiming; Stoumpos, Constantinos C. ACS Nano, Vol. 10, Issue 8 https://doi.org/10.1021/acsnano.6b03916	journal	July 2016
Importance of Spin–Orbit Coupling in Hybrid Organic/Inorganic Perovskites for Photovoltaic Applications Even, Jacky; Pedesseau, Laurent; Jancu, Jean-Marc The Journal of Physical Chemistry Letters, Vol. 4, Issue 17 https://doi.org/10.1021/jz401532q	journal	August 2013
White-Light Emission from Layered Halide Perovskites Smith, Matthew D.; Karunadasa, Hemamala I. Accounts of Chemical Research, Vol. 51, Issue 3 https://doi.org/10.1021/acs.accounts.7b00433	journal	February 2018
Guanidinium-Formamidinium Lead Iodide: A Layered Perovskite-Related Compound with Red Luminescence at Room Temperature Nazarenko, Olga; Kotyrba, Martin R.; Yakunin, Sergii Journal of the American Chemical Society, Vol. 140, Issue 11 https://doi.org/10.1021/jacs.8b00194	journal	February 2018
Electron–phonon coupling in hybrid lead halide perovskites Wright, Adam D.; Verdi, Carla; Milot, Rebecca L. Nature Communications, Vol. 7, Issue 1 https://doi.org/10.1038/ncomms11755	journal	May 2016
Crystal structure of tetrakis(ethylammonium) decachlorotriplumbate(II), (C2H5NH3)4Pb3Cl10 Geselle, M.; Fuess, H. Zeitschrift für Kristallographie - New Crystal Structures, Vol. 212, Issue JG https://doi.org/10.1524/ncrs.1997.212.jg.241	journal	January 1997
Ferroelectric large polarons Miyata, Kiyoshi; Zhu, X. -Y. Nature Materials, Vol. 17, Issue 5 https://doi.org/10.1038/s41563-018-0068-7	journal	April 2018
Organic–Inorganic Hybrid Lead Iodide Perovskite Featuring Zero Dipole Moment Guanidinium Cations: A Theoretical Analysis Giorgi, Giacomo; Fujisawa, Jun-Ichi; Segawa, Hiroshi The Journal of Physical Chemistry C, Vol. 119, Issue 9 https://doi.org/10.1021/acs.jpcc.5b00051	journal	February 2015
Steric engineering of metal-halide perovskites with tunable optical band gaps Filip, Marina R.; Eperon, Giles E.; Snaith, Henry J. Nature Communications, Vol. 5, Issue 1 https://doi.org/10.1038/ncomms6757	journal	December 2014
Effect of guanidinium on mesoscopic perovskite solar cells Hou, Xiaomeng; Hu, Yue; Liu, Huawei Journal of Materials Chemistry A, Vol. 5, Issue 1 https://doi.org/10.1039/C6TA08418D	journal	January 2017
Tunable White-Light Emission in Single-Cation-Templated Three-Layered 2D Perovskites (CH ₃ CH ₂ NH ₃ ) ₄ Pb ₃ Br _{10– x} Cl _x Mao, Lingling; Wu, Yilei; Stoumpos, Constantinos C. Journal of the American Chemical Society, Vol. 139, Issue 34 https://doi.org/10.1021/jacs.7b06143	journal	August 2017
Two-Dimensional Lead(II) Halide-Based Hybrid Perovskites Templated by Acene Alkylamines: Crystal Structures, Optical Properties, and Piezoelectricity Du, Ke-zhao; Tu, Qing; Zhang, Xu Inorganic Chemistry, Vol. 56, Issue 15 https://doi.org/10.1021/acs.inorgchem.7b01094	journal	July 2017
New Type of 2D Perovskites with Alternating Cations in the Interlayer Space, (C(NH ₂ ) ₃ )(CH ₃ NH ₃ ) _n Pb _n I _{3 n +1} : Structure, Properties, and Photovoltaic Performance Soe, Chan Myae Myae; Stoumpos, Constantinos C.; Kepenekian, Mikaël Journal of the American Chemical Society, Vol. 139, Issue 45 https://doi.org/10.1021/jacs.7b09096	journal	November 2017