1
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Paliwal A, Zanoni KPS, Roldán-Carmona C, Rodkey N, Bolink HJ. Vacuum-Deposited Bifacial Perovskite Solar Cells. ACS ENERGY LETTERS 2024; 9:4587-4595. [PMID: 39296966 PMCID: PMC11406524 DOI: 10.1021/acsenergylett.4c01536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/28/2024] [Accepted: 08/01/2024] [Indexed: 09/21/2024]
Abstract
Bifacial perovskite solar cells (Bi-PSCs) require thick perovskite layers to sufficiently absorb higher wavelength light. Also, it is critical to know which electrode (top or bottom) can more efficiently harvest the direct incident solar irradiance. Here, fully vacuum-deposited Bi-PSCs are reported with perovskite layer thicknesses ranging from ∼720 nm to 1.3 μm. With an optimized ITO top-electrode, the Bi-PSCs generated higher current density under top-illumination by >1 mA/cm2, attaining the highest value of 24.98 mA/cm2. The best Bi-PSC exhibited an efficiency of 19.6% under top-illumination and 18.71% under bottom-illumination, resulting in a high bifaciality factor of ∼0.95. Furthermore, even after employing cover glass encapsulation on the top-electrode, the Bi-PSCs still produced higher current density from top-illumination. Upon bifacial illumination using simulated 1-Sun light as the main illumination and a white LED light albedo of ∼0.21, the champion Bi-PSC demonstrated a current density value of ∼30.00 mA/cm2.
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Affiliation(s)
- Abhyuday Paliwal
- Instituto de Ciencia Molecular, Universidad de Valencia, Calle Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Kassio P S Zanoni
- Instituto de Ciencia Molecular, Universidad de Valencia, Calle Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Cristina Roldán-Carmona
- Instituto de Ciencia Molecular, Universidad de Valencia, Calle Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Nathan Rodkey
- Instituto de Ciencia Molecular, Universidad de Valencia, Calle Catedrático José Beltrán 2, 46980 Paterna, Spain
| | - Henk J Bolink
- Instituto de Ciencia Molecular, Universidad de Valencia, Calle Catedrático José Beltrán 2, 46980 Paterna, Spain
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2
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Yan N, Cao Y, Jin Z, Liu Y, Liu SF, Fang Z, Feng J. Surface Reconstruction for Efficient NiO x-Based Inverted Perovskite Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403682. [PMID: 38701489 DOI: 10.1002/adma.202403682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/27/2024] [Indexed: 05/05/2024]
Abstract
Functional agents are verified to efficiently enhance device performance of perovskite solar cells (PSCs) through surface engineering. However, the influence of intrinsic characteristics of molecules on final device performance is overlooked. Here, a surface reconstruction strategy is developed to enhance the efficiency of inverted PSCs by mitigating the adverse effects of lead chelation (LC) molecules. Bathocuproine (BCP) is chosen as the representative of LC molecules for its easy accessibility and outstanding optoelectronic properties. During this strategy, BCP molecules on perovskite surface are first dissolved in solvents and then captured specially by undercoordinated Pb2+ ions, preventing adverse n-type doping by the molecules themselves. In this case, the BCP molecule exhibits outstanding passivation effect on perovskite surface, which leads to an obviously increased open-circuit voltage (VOC). Therefore, a record power conversion efficiency of 25.64% for NiOx-based inverted PSCs is achieved, maintaining over 80% of initial efficiency after exposure to ambient condition for ≈1500 h.
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Affiliation(s)
- Nan Yan
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Yang Cao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Zhiwen Jin
- School of Physical Science and Technology, Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou, 730000, China
| | - Yucheng Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Shengzhong Frank Liu
- Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhimin Fang
- Institute of Technology for Carbon Neutralization, Yangzhou University, Yangzhou, Jiangsu, 225127, China
| | - Jiangshan Feng
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China
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3
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Yan S, Patel JB, Lee JE, Elmestekawy KA, Ratnasingham SR, Yuan Q, Herz LM, Noel NK, Johnston MB. A Templating Approach to Controlling the Growth of Coevaporated Halide Perovskites. ACS ENERGY LETTERS 2023; 8:4008-4015. [PMID: 37854049 PMCID: PMC10580315 DOI: 10.1021/acsenergylett.3c01368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/25/2023] [Indexed: 10/20/2023]
Abstract
Metal halide perovskite semiconductors have shown significant potential for use in photovoltaic (PV) devices. While fabrication of perovskite thin films can be achieved through a variety of techniques, thermal vapor deposition is particularly promising, allowing for high-throughput fabrication. However, the ability to control the nucleation and growth of these materials, particularly at the charge-transport layer/perovskite interface, is critical to unlocking the full potential of vapor-deposited perovskite PV. In this study, we explore the use of a templating layer to control the growth of coevaporated perovskite films and find that such templating leads to highly oriented films with identical morphology, crystal structure, and optoelectronic properties independent of the underlying layers. Solar cells incorporating templated FA0.9Cs0.1PbI3-xClx show marked improvements with steady-state power conversion efficiency over 19.8%. Our findings provide a straightforward and reproducible method of controlling the charge-transport layer/coevaporated perovskite interface, further clearing the path toward large-scale fabrication of efficient PV devices.
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Affiliation(s)
- Siyu Yan
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Jay B. Patel
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Jae Eun Lee
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Karim A. Elmestekawy
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Sinclair R. Ratnasingham
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Qimu Yuan
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Laura M. Herz
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
- Institute
for Advanced Study, Technical University
of Munich, Munich, Lichtenbergstrasse 2a, D-85748 Garching Germany
| | - Nakita K. Noel
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Michael B. Johnston
- Department
of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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4
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Wargulski DR, Xu K, Hempel H, Flatken MA, Albrecht S, Abou-Ras D. Relationship between the Annealing Temperature and the Presence of PbI 2 Platelets at the Surfaces of Slot-Die-Coated Triple-Halide Perovskite Thin Films. ACS APPLIED MATERIALS & INTERFACES 2023; 15:41516-41524. [PMID: 37626018 PMCID: PMC10485798 DOI: 10.1021/acsami.3c07692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023]
Abstract
We investigated triple-halide perovskite (THP) absorber layers with 5 mol % MAPbCl3 added to the double-halide perovskite (Cs0.22FA0.78)Pb(I0.85Br0.15)3. As a deposition method, a highly scalable printing technique, slot-die coating, with a subsequent annealing step was used. We found a strong power conversion efficiency (PCE) dependence of the corresponding solar cells on the annealing temperature. The device performance deteriorated when increasing the annealing temperature from 125 to 170 °C, mainly via losses in the open-circuit voltage (Voc) and in the fill factor (FF). To understand the mechanisms behind this performance loss, extensive characterizations were performed on both, the THP thin films and the completed solar-cell stacks, as a function of annealing temperature. Correlative scanning electron microscopy analyses, i.e., electron backscatter diffraction, energy-dispersive X-ray spectroscopy, and cathodoluminescence, in addition to X-ray diffraction and photoluminescence, confirmed the presence of PbI2 platelets on the surface of the THP thin films. Moreover, the area fraction of the PbI2 platelets on the film surface increased with increasing annealing temperature. The deteriorated device performance when the annealing temperature is increased from 125 to 170 °C is explained by the increased series resistance and increased interface recombination caused by the PbI2 platelets, leading to decreased Voc and FF values of the solar-cell devices. Thus, the correlative analyses provided insight into microscopic origins of the efficiency losses.
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Affiliation(s)
- Dan R. Wargulski
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Ke Xu
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Hannes Hempel
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Marion A. Flatken
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Steve Albrecht
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
- Faculty
of Electrical Engineering and Computer Science, Technische Universität Berlin, 10587 Berlin, Germany
| | - Daniel Abou-Ras
- Helmholtz-
Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany
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5
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Li D, Dong X, Cheng P, Song L, Wu Z, Chen Y, Huang W. Metal Halide Perovskite/Electrode Contacts in Charge-Transporting-Layer-Free Devices. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203683. [PMID: 36319474 PMCID: PMC9798992 DOI: 10.1002/advs.202203683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Metal halide perovskites have drawn substantial interest in optoelectronic devices in the past decade. Perovskite/electrode contacts are crucial for constructing high-performance charge-transporting-layer-free perovskite devices, such as solar cells, field-effect transistors, artificial synapses, memories, etc. Many studies have evidenced that the perovskite layer can directly contact the electrodes, showing abundant physicochemical, electronic, and photoelectric properties in charge-transporting-layer-free perovskite devices. Meanwhile, for perovskite/metal contacts, some critical interfacial physical and chemical processes are reported, including band bending, interface dipoles, metal halogenation, and perovskite decomposition induced by metal electrodes. Thus, a systematic summary of the role of metal halide perovskite/electrode contacts on device performance is essential. This review summarizes and discusses charge carrier dynamics, electronic band engineering, electrode corrosion, electrochemical metallization and dissolution, perovskite decomposition, and interface engineering in perovskite/electrode contacts-based electronic devices for a comprehensive understanding of the contacts. The physicochemical, electronic, and morphological properties of various perovskite/electrode contacts, as well as relevant engineering techniques, are presented. Finally, the current challenges are analyzed, and appropriate recommendations are put forward. It can be expected that further research will lead to significant breakthroughs in their application and promote reforms and innovations in future solid-state physics and materials science.
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Affiliation(s)
- Deli Li
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
- Fujian cross Strait Institute of Flexible Electronics (Future Technologies)Fujian Normal UniversityFuzhou350117P. R. China
| | - Xue Dong
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
| | - Peng Cheng
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
| | - Lin Song
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
| | - Zhongbin Wu
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
| | - Yonghua Chen
- Key Laboratory of Flexible Electronics (KLoFE) and Institute of Advanced Materials (IAM)Nanjing Tech University30 South Puzhu RoadNanjingJiangsu211816P. R. China
| | - Wei Huang
- Frontiers Science Center for Flexible ElectronicsXi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials and EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi'an710072P. R. China
- Key Laboratory of Flexible Electronics (KLoFE) and Institute of Advanced Materials (IAM)Nanjing Tech University30 South Puzhu RoadNanjingJiangsu211816P. R. China
- Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced MaterialsNanjing University of Posts and TelecommunicationsNanjing210023P. R. China
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6
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Yoon J, Liu X, Lee EC. Defect Passivation via Isoxazole Doping in Perovskite Solar Cells. ACS OMEGA 2022; 7:34278-34285. [PMID: 36188244 PMCID: PMC9520746 DOI: 10.1021/acsomega.2c03775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/01/2022] [Indexed: 06/16/2023]
Abstract
To improve perovskite solar cell (PSC) performance, which is deeply related to perovskite layer quality, researchers have explored numerous strategies. Additive doping into perovskite precursors has been widely used to improve the PSC performance. In this study, we used isoxazole-a Lewis-base small molecule-as an additive for the CH3NH3PbI3 (MAPbI3) precursor and explored how isoxazole effectively passivates defects in the perovskite structure. We found that isoxazole interacted with undercoordinated Pb2+ ions from an X-ray photoelectron spectroscopy survey and verified that isoxazole doping improved the device performance. When the optimized concentration of isoxazole was doped in the MAPbI3 precursor, the power conversion efficiency increased from 15.6 to 17.5%, with an improved fill factor and short-circuit current density. In addition, an isoxazole-doped device sustained 94% of its initial performance after 8 days under ambient air conditions (10 ± 5 RH %, 25 °C), whereas a device without isoxazole doping only maintained 64% of its initial performance.
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Affiliation(s)
- Jinho Yoon
- Department
of Nanoscience and Technology, Graduate School, Gachon University, Seongnam, Gyeonggi 13120, Republic of Korea
| | - Xuewen Liu
- Department
of Physics, Gachon University, Seongnam, Gyeonggi 13120, Republic of Korea
| | - Eun-Cheol Lee
- Department
of Nanoscience and Technology, Graduate School, Gachon University, Seongnam, Gyeonggi 13120, Republic of Korea
- Department
of Physics, Gachon University, Seongnam, Gyeonggi 13120, Republic of Korea
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7
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Castro-Méndez AF, Perini CAR, Hidalgo J, Ranke D, Vagott JN, An Y, Lai B, Luo Y, Li R, Correa-Baena JP. Formation of a Secondary Phase in Thermally Evaporated MAPbI 3 and Its Effects on Solar Cell Performance. ACS APPLIED MATERIALS & INTERFACES 2022; 14:34269-34280. [PMID: 35561234 DOI: 10.1021/acsami.2c02036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Thermal evaporation is a promising deposition technique to scale up perovskite solar cells (PSCs) to large areas, but the lack of understanding of the mechanisms that lead to high-quality evaporated methylammonium lead triiodide (MAPbI3) films gives rise to devices with efficiencies lower than those obtained by spin coating. This work investigates the crystalline properties of MAPbI3 deposited by the thermal coevaporation of PbI2 and MAI, where the MAI evaporation rate is controlled by setting different temperatures for the MAI source and the PbI2 deposition rate is controlled with a quartz crystal microbalance (QCM). Using grazing incident wide-angle X-ray scattering (GIWAXS) and X-ray diffraction (XRD), we identify the formation of a secondary orthorhombic phase (with a Pnma space group) that appears at MAI source temperatures below 155 °C. With synchrotron-based X-ray fluorescence (XRF) microscopy, we show that the changes in crystalline phases are not necessarily due to changes in stoichiometry. The films show a stochiometric composition when the MAI source is heated between 140 to 155 °C, and the samples become slightly MAI rich at 165 °C. Increasing the MAI temperature beyond 165 °C introduces an excess of MAI in the film, which promotes the formation of films with low crystallinity that contain low-dimensional perovskites. When they are incorporated in solar cells, the films deposited at 165 °C result in the champion power conversion efficiency, although the presence of a small amount of low-dimensional perovskite may lead to a lower open-circuit voltage. We hypothesize that the formation of secondary phases in evaporated films limits the performance of PSCs and that their formation can be suppressed by controlling the MAI source temperature, bringing the film toward a phase-pure tetragonal structure. Control of the phases during perovskite evaporation is therefore crucial to obtain high-performance solar cells.
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Affiliation(s)
- Andrés-Felipe Castro-Méndez
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Carlo A R Perini
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Juanita Hidalgo
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Daniel Ranke
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Jacob N Vagott
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Yu An
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
| | - Barry Lai
- Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
| | - Yanqi Luo
- Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
| | - Ruipeng Li
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Juan-Pablo Correa-Baena
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue NW, Atlanta, Georgia 30332, United States
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8
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Klipfel N, Kanda H, Sutanto AA, Mensi M, Igci C, Leifer K, Brooks K, Kinge S, Roldán-Carmona C, Momblona C, Dyson PJ, Nazeeruddin MK. Mechanistic Insights into the Role of the Bis(trifluoromethanesulfonyl)imide Ion in Coevaporated p-i-n Perovskite Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:52450-52460. [PMID: 34704729 DOI: 10.1021/acsami.1c10117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hybrid lead halide perovskites have reached comparable efficiencies to state-of-the-art silicon solar cell technologies. However, a remaining key challenge toward commercialization is the resolution of the perovskite device instability. In this work, we identify for the first time the mobile nature of bis(trifluoromethanesulfonyl)imide (TFSI-), a typical anion extensively employed in p-type dopants for 2,2'7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'spirofluorene (spiro-OMeTAD). We demonstrate that TFSI- can migrate through the perovskite layer via the grain boundaries and accumulate at the perovskite/electron-transporting layer (ETL) interface. Our findings reveal that the migration of TFSI- enhances the device performance and stability, resulting in highly stable p-i-n cells that retain 90% of their initial performance after 1600 h of continuous testing. Our systematic study, which targeted the effect of the nature of the dopant and its concentration, also shows that TFSI- acts as a dynamic defect-healing agent, which self-passivates the perovskite crystal defects during the migration process and thereby decreases nonradiative recombination pathways.
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Affiliation(s)
- Nadja Klipfel
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Hiroyuki Kanda
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Albertus Adrian Sutanto
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Mounir Mensi
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Cansu Igci
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Klaus Leifer
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
- Department of Materials Science and Engineering, Uppsala University, Box 534, 75121 Uppsala, Sweden
| | - Keith Brooks
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Sachin Kinge
- Toyota Motor Corporation, Toyota Motor Technical Centre, Advanced Technology Division, Hoge Wei 33, B-1930 Zaventem, Belgium
| | - Cristina Roldán-Carmona
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Cristina Momblona
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Paul J Dyson
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
| | - Mohammad Khaja Nazeeruddin
- Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL Valais Wallis), Rue de l'Industrie 17, CH-1951 Sion, Switzerland
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9
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Li D, Chao L, Chen C, Ran X, Wang Y, Niu T, Lv S, Wu H, Xia Y, Ran C, Song L, Chen S, Chen Y, Huang W. In Situ Interface Engineering for Highly Efficient Electron-Transport-Layer-Free Perovskite Solar Cells. NANO LETTERS 2020; 20:5799-5806. [PMID: 32634316 DOI: 10.1021/acs.nanolett.0c01689] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electron-transport-layer free perovskite solar cells (ETL-free PSCs) have attracted great attention due to their low cost and simple manufacturing process. However, an additional interface layer has to be introduced, and the currently achieved efficiency remains far from full-structure PSCs. Here, we report an in situ interface engineering strategy by the methylammonium acetate (MAAc) ionic liquid perovskite precursor. We found that a dipole layer was in situ constructed through the physical adsorption of the residual MAAc polar molecules on the indium tin oxide electrode, which is significantly different from the treatment by the interface layer in previous reports. This allows a decrease of the effective work function and enables in situ band bending in the perovskite semiconductor. The in situ band bending facilitates charge collection and hinders interfacial charge recombination, leading to ETL-free PSCs with a maximum power conversion efficiency of 21.08%, which is the highest report to date.
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Affiliation(s)
- Deli Li
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Lingfeng Chao
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Changshun Chen
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Xueqin Ran
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, Jiangsu 211816, China
| | - Yue Wang
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Tingting Niu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Shaoshen Lv
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Hui Wu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Yingdong Xia
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, Jiangsu 211816, China
| | - Chenxin Ran
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Lin Song
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Shi Chen
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China
| | - Yonghua Chen
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, Jiangsu 211816, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE), and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, Jiangsu 211816, China
- Key Laboratory for Organic Electronics & Information Displays (KLOEID), and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210023, China
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10
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Kim S, Jeong JE, Hong J, Lee K, Lee MJ, Woo HY, Hwang I. Improved Interfacial Crystallization by Synergic Effects of Precursor Solution Stoichiometry and Conjugated Polyelectrolyte Interlayer for High Open-Circuit Voltage of Perovskite Photovoltaic Diodes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:12328-12336. [PMID: 31997636 DOI: 10.1021/acsami.9b22283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The open-circuit voltage (Voc) of perovskite photovoltaic diodes depends largely on the selection of charge transport layers (CTLs) and surface passivation, which makes it important to understand the physical processes occurring at the interface between the perovskite and a CTL. We provide a direct correlation between Voc and the interfacial characteristics of perovskites tuned through stoichiometry engineering of precursor solutions and surface modification of the underlying poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) layer. Poor quality interfacial perovskite crystals were observed on top of the PEDOT:PSS layer, resulting in strong interfacial recombination and a low Voc. In contrast, the growth of the interfacial perovskite crystals was significantly improved by the synergic effects of varying the precursor solution composition and covering the surface with a pH-neutral conjugated polyelectrolyte, poly[2,6-(4,4-bis(potassium butanylsulfonate)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (CPE-K), which possesses potassium ions as counter ions. The influence of the energy-level alignment at the interface on Voc was also discussed. Our findings highlight that improved perovskite crystallization at the interface can facilitate bulk growth of perovskite grains in the vertical direction and effectively suppress nonradiative surface charge recombination, thus enhancing the short-circuit current and Voc.
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Affiliation(s)
- Sohyeon Kim
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
| | - Ji-Eun Jeong
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - Jungyun Hong
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
| | - Kangmin Lee
- School of Advanced Materials Engineering, Kookmin University, Seoul 02707, Republic of Korea
| | - Mi Jung Lee
- School of Advanced Materials Engineering, Kookmin University, Seoul 02707, Republic of Korea
| | - Han Young Woo
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - Inchan Hwang
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
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11
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Shallcross RC, Olthof S, Meerholz K, Armstrong NR. Impact of Titanium Dioxide Surface Defects on the Interfacial Composition and Energetics of Evaporated Perovskite Active Layers. ACS APPLIED MATERIALS & INTERFACES 2019; 11:32500-32508. [PMID: 31390181 DOI: 10.1021/acsami.9b09935] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This investigation elucidates critical Brønsted and Lewis acid-base interactions at the titanium dioxide (TiO2) surface that control the interfacial composition and, thus, the energetics of vacuum-processed methylammonium lead iodide (MAPbI3) perovskite active layers (PALs). In situ photoelectron spectroscopy analysis shows that interfacial growth, chemical composition, and energetics of co-deposited methylammonium iodide (MAI)/PbI2 thin films are significantly different on bare and (3-aminopropyl)triethoxysilane (APTES)-functionalized TiO2 surfaces. Mass spectroscopy analysis indicates that MAI dissociates into hydrogen iodide and methylamine in the gas phase and suggests that MAPbI3 nucleation is preceded by adsorption and coupling of these volatile MAI precursors. Prior to MAPbI3 nucleation on the bare TiO2 surface, we suggest that high coverages of methylamine adsorbed to surface defect sites (e.g., undercoordinated Ti atoms and hydroxyls) promote island-like growth of large, PbI2-rich nuclei that inhibit nucleation and lead to a thick substoichiometric interface layer that impedes charge transport and collection energetics. APTES functional groups passivate TiO2 surface defects and facilitate more conformal growth of small, PbI2-rich nuclei that enhance MAPbI3 nucleation and significantly improve interfacial energetics for charge transport and extraction. This work highlights the considerable influence of TiO2 surface chemistry on PAL composition and energetics, which are critical factors that impact the performance and long stability of these materials in emerging photovoltaic device technologies.
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Affiliation(s)
- R Clayton Shallcross
- Department of Chemistry and Biochemistry , University of Arizona , Tucson , Arizona 85721 , United States
| | - Selina Olthof
- Department of Chemistry , University of Cologne , Luxemburger Str. 116 , 50939 Cologne , Germany
| | - Klaus Meerholz
- Department of Chemistry , University of Cologne , Luxemburger Str. 116 , 50939 Cologne , Germany
| | - Neal R Armstrong
- Department of Chemistry and Biochemistry , University of Arizona , Tucson , Arizona 85721 , United States
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12
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Parrott ES, Patel JB, Haghighirad AA, Snaith HJ, Johnston MB, Herz LM. Growth modes and quantum confinement in ultrathin vapour-deposited MAPbI 3 films. NANOSCALE 2019; 11:14276-14284. [PMID: 31317998 DOI: 10.1039/c9nr04104d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Vapour deposition of metal halide perovskite by co-evaporation of precursors has the potential to achieve large-area high-efficiency solar cells on an industrial scale, yet little is known about the growth of metal halide perovskites by this method at the current time. Here, we report the fabrication of MAPbI3 films with average thicknesses from 2-320 nm by co-evaporation. We analyze the film properties using X-ray diffraction, optical absorption and photoluminescence (PL) to provide insights into the nucleation and growth of MAPbI3 films on quartz substrates. We find that the perovskite initially forms crystallite islands of around 8 nm in height, which may be the cause of the persistent small grain sizes reported for evaporated metal halide perovskites that hinder device efficiency and stability. As more material is added, islands coalesce until full coverage of the substrate is reached at around 10 nm average thickness. We also find that quantum confinement induces substantial shifts to the PL wavelength when the average thickness is below 40 nm, offering dual-source vapour deposition as an alternative method of fabricating nanoscale structures for LEDs and other devices.
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Affiliation(s)
- Elizabeth S Parrott
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK.
| | - Jay B Patel
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK.
| | | | - Henry J Snaith
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK.
| | - Michael B Johnston
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK.
| | - Laura M Herz
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK.
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13
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Abstract
Design and modification of interfaces, always a critical issue for semiconductor devices, has become a primary tool to harness the full potential of halide perovskite (HaP)-based optoelectronics, including photovoltaics and light-emitting diodes. In particular, the outstanding improvements in HaP solar cell performance and stability can be primarily ascribed to a careful choice of the interfacial layout in the layer stack. In this review, we describe the unique challenges and opportunities of these approaches (section 1). For this purpose, we first elucidate the basic physical and chemical properties of the exposed HaP thin film and crystal surfaces, including topics such as surface termination, surface reactivity, and electronic structure (section 2). This is followed by discussing experimental results on the energetic alignment processes at the interfaces between the HaP and transport and buffer layers. This section includes understandings reached as well as commonly proposed and applied models, especially the often-questionable validity of vacuum level alignment, the importance of interface dipoles, and band bending as the result of interface formation (section 3). We follow this by elaborating on the impact of the interface formation on device performance, considering effects such as chemical reactions and surface passivation on interface energetics and stability. On the basis of these concepts, we propose a roadmap for the next steps in interfacial design for HaP semiconductors (section 4), emphasizing the importance of achieving control over the interface energetics and chemistry (i.e., reactivity) to allow predictive power for tailored interface optimization.
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Affiliation(s)
- Philip Schulz
- Institut Photovoltaïque d'Île-de-France (IPVF) , 91120 Palaiseau , France.,CNRS , Institut Photovoltaı̈que d'Île de France (IPVF) , UMR 9006 , 91120 Palaiseau , France.,National Center for Photovoltaics , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - David Cahen
- Department of Materials and Interfaces , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Antoine Kahn
- Department of Electrical Engineering , Princeton University , Princeton , New Jersey 08544 , United States
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14
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Fallah Hamidabadi V, Momblona C, Pérez-Del-Rey D, Bahari A, Sessolo M, Bolink HJ. Phosphomolybdic acid as an efficient hole injection material in perovskite optoelectronic devices. Dalton Trans 2019; 48:30-34. [DOI: 10.1039/c8dt03680b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phosphomolybdic acid (PMA) is a solution-processable high work function material which can be used as hole-injection interface in perovskite solar cells and LEDs.
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Affiliation(s)
| | | | | | - Ali Bahari
- Department of Physics
- Faculty of Basic Sciences
- University of Mazandaran
- Babolsar 47416-95447
- Iran
| | - Michele Sessolo
- Instituto de Ciencia Molecular
- Universidad de Valencia
- Paterna
- Spain
| | - Henk J. Bolink
- Instituto de Ciencia Molecular
- Universidad de Valencia
- Paterna
- Spain
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15
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Dunlap-Shohl WA, Zhou Y, Padture NP, Mitzi DB. Synthetic Approaches for Halide Perovskite Thin Films. Chem Rev 2018; 119:3193-3295. [DOI: 10.1021/acs.chemrev.8b00318] [Citation(s) in RCA: 334] [Impact Index Per Article: 55.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Wiley A. Dunlap-Shohl
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
| | - Yuanyuan Zhou
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Nitin P. Padture
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - David B. Mitzi
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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16
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Lang F, Shargaieva O, Brus VV, Neitzert HC, Rappich J, Nickel NH. Influence of Radiation on the Properties and the Stability of Hybrid Perovskites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30. [PMID: 29152795 DOI: 10.1002/adma.201702905] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/29/2017] [Indexed: 05/06/2023]
Abstract
Organic-inorganic perovskites are well suited for optoelectronic applications. In particular, perovskite single and perovskite tandem solar cells with silicon are close to their market entry. Despite their swift rise in efficiency to more than 21%, solar cell lifetimes are way below the needed 25 years. In fact, comparison of the time when the device performance has degraded to 80% of its initial value (T80 lifetime) of numerous solar cells throughout the literature reveals a strongly reduced stability under illumination. Herein, the various detrimental effects are discussed. Most notably, moisture- and heat-related degradation can be mitigated easily by now. Recently, however, several photoinduced degradation mechanisms have been observed. Under illumination, mixed perovskites tend to phase segregate, while, further, oxygen catalyzes deprotonation of the organic cations. Additionally, during illumination photogenerated charge can be trapped in the NH antibonding orbitals causing dissociation of the organic cation. On the other hand, organic-inorganic perovskites exhibit a high radiation hardness that is superior to crystalline silicon. Here, the proposed degradation mechanisms reported in the literature are thoroughly reviewed and the microscopic mechanisms and their implications for solar cells are discussed.
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Affiliation(s)
- Felix Lang
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Silizium Photovoltaik, Kekuléstr. 5, 12489, Berlin, Germany
| | - Oleksandra Shargaieva
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Silizium Photovoltaik, Kekuléstr. 5, 12489, Berlin, Germany
| | - Viktor V Brus
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Silizium Photovoltaik, Kekuléstr. 5, 12489, Berlin, Germany
| | - Heinz C Neitzert
- Department of Industrial Engineering (DIIn), Salerno University, Via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Jörg Rappich
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Silizium Photovoltaik, Kekuléstr. 5, 12489, Berlin, Germany
| | - Norbert H Nickel
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institut für Silizium Photovoltaik, Kekuléstr. 5, 12489, Berlin, Germany
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17
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Xiao C, Wang C, Ke W, Gorman BP, Ye J, Jiang CS, Yan Y, Al-Jassim MM. Junction Quality of SnO 2-Based Perovskite Solar Cells Investigated by Nanometer-Scale Electrical Potential Profiling. ACS APPLIED MATERIALS & INTERFACES 2017; 9:38373-38380. [PMID: 29027466 DOI: 10.1021/acsami.7b08582] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electron-selective layers (ESLs) and hole-selective layers (HSLs) are critical in high-efficiency organic-inorganic lead halide perovskite (PS) solar cells for charge-carrier transport, separation, and collection. We developed a procedure to assess the quality of the ESL/PS junction by measuring potential distribution on the cross section of SnO2-based PS solar cells using Kelvin probe force microscopy. Using the potential profiling, we compared three types of cells made of different ESLs but otherwise having an identical device structure: (1) cells with PS deposited directly on bare fluorine-doped SnO2 (FTO)-coated glass; (2) cells with an intrinsic SnO2 thin layer on the top of FTO as an effective ESL; and (3) cells with the SnO2 ESL and adding a self-assembled monolayer (SAM) of fullerene. The results reveal two major potential drops or electric fields at the ESL/PS and PS/HSL interfaces. The electric-field ratio between the ESL/PS and PS/HSL interfaces increased in devices as follows: FTO < SnO2-ESL < SnO2 + SAM; this sequence explains the improvements of the fill factor (FF) and open-circuit voltage (Voc). The improvement of the FF from the FTO to SnO2-ESL cells may result from the reduction in voltage loss at the PS/HSL back interface and the improvement of Voc from the prevention of hole recombination at the ESL/PS front interface. The further improvements with adding an SAM is caused by the defect passivation at the ESL/PS interface, and hence, improvement of the junction quality. These nanoelectrical findings suggest possibilities for improving the device performance by further optimizing the SnO2-based ESL material quality and the ESL/PS interface.
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Affiliation(s)
- Chuanxiao Xiao
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
- Colorado School of Mines , Golden, Colorado 80401, United States
| | - Changlei Wang
- The University of Toledo , Toledo, Ohio 43606, United States
| | - Weijun Ke
- The University of Toledo , Toledo, Ohio 43606, United States
| | - Brian P Gorman
- Colorado School of Mines , Golden, Colorado 80401, United States
| | - Jichun Ye
- Ningbo Institute of Industrial Technology, Chinese Academy of Science , Ningbo, Zhejiang Province 315201, China
| | - Chun-Sheng Jiang
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| | - Yanfa Yan
- The University of Toledo , Toledo, Ohio 43606, United States
| | - Mowafak M Al-Jassim
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
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18
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Shallcross RC, Zheng Y, Saavedra SS, Armstrong NR. Determining Band-Edge Energies and Morphology-Dependent Stability of Formamidinium Lead Perovskite Films Using Spectroelectrochemistry and Photoelectron Spectroscopy. J Am Chem Soc 2017; 139:4866-4878. [DOI: 10.1021/jacs.7b00516] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Clayton Shallcross
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Yilong Zheng
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - S. Scott Saavedra
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Neal R. Armstrong
- Department of Chemistry and
Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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19
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Olthof S, Meerholz K. Substrate-dependent electronic structure and film formation of MAPbI 3 perovskites. Sci Rep 2017; 7:40267. [PMID: 28084313 PMCID: PMC5234022 DOI: 10.1038/srep40267] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/05/2016] [Indexed: 12/24/2022] Open
Abstract
We present investigations on the interface formation between the hybrid perovskite MAPbI3 and various substrates, covering a wide range of work functions. The perovskite films are incrementally evaporated in situ while the electronic structure is evaluated using photoelectron spectroscopy. Our results show that there is an induction period in the growth of the perovskite during which volatile compounds are formed, catalyzed by the substrate. The duration of the induction period depends strongly on the nature of the substrate material, and it can take up to 20–30 nm of formal precursor deposition before the surface is passivated and the perovskite film starts forming. The stoichiometry of the 2–3 nm thin passivation layer deviates from the expected perovskite stoichiometry, being rich in decomposition products of the organic cation. During the regular growth of the perovskite, our measurements show a deviation from the commonly assumed flat band condition, i.e., dipole formation and band bending dominate the interface. Overall, the nature of the substrate not only changes the energetic alignment of the perovskite, it can introduce gap states and influence the film formation and morphology. The possible impact on device performance is discussed.
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Affiliation(s)
- Selina Olthof
- Department of Chemistry, University of Cologne, Luxemburger Straße 116, 50939 Cologne Germany
| | - Klaus Meerholz
- Department of Chemistry, University of Cologne, Luxemburger Straße 116, 50939 Cologne Germany
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