Real-Time Observation of Iodide Ion Migration in Methylammonium Lead Halide Perovskites.

Organic-inorganic metal halide perovskites (e.g., CH3 NH3 PbI3-x Clx ) emerge as a promising optoelectronic material. However, the Shockley-Queisser limit for the power conversion efficiency (PCE) of perovskite-based photovoltaic devices is still not reached. Nonradiative recombination pathways may play a significant role and appear as photoluminescence (PL) inactive (or dark) areas on perovskite films. Although these observations are related to the presence of ions/defects, the underlying fundamental physics and detailed microscopic processes, concerning trap/defect status, ion migration, etc., still remain poorly understood. Here correlated wide-field PL microscopy and impedance spectroscopy are utilized on perovskite films to in situ investigate both the spatial and the temporal evolution of these PL inactive areas under external electric fields. The formation of PL inactive domains is attributed to the migration and accumulation of iodide ions under external fields. Hence, we are able to characterize the kinetic processes and determine the drift velocities of these ions. In addition, it is shown that I2 vapor directly affects the PL quenching of a perovskite film, which provides evidence that the migration/segregation of iodide ions plays an important role in the PL quenching and consequently limits the PCE of organometal halide-based perovskite photovoltaic devices.

[1]  K. B. Oldham.  A Gouy–Chapman–Stern model of the double layer at a (metal)/(ionic liquid) interface , 2008 .

[2]  R. Hildner,et al.  Long-range energy transport in single supramolecular nanofibres at room temperature , 2015, Nature.

[3]  Henk J. Bolink,et al.  Radiative efficiency of lead iodide based perovskite solar cells , 2014, Scientific Reports.

[4]  J. Galisteo‐López,et al.  Environmental Effects on the Photophysics of Organic–Inorganic Halide Perovskites , 2015, The journal of physical chemistry letters.

[5]  A. Zaban,et al.  Perovskites for Photovoltaics in the Spotlight: Photoinduced Physical Changes and Their Implications. , 2016, Accounts of chemical research.

[6]  Kaibo Zheng,et al.  Mechanistic insights into perovskite photoluminescence enhancement: light curing with oxygen can boost yield thousandfold. , 2015, Physical chemistry chemical physics : PCCP.

[7]  Tsutomu Miyasaka,et al.  Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. , 2009, Journal of the American Chemical Society.

[8]  Henry J Snaith,et al.  Metal-halide perovskites for photovoltaic and light-emitting devices. , 2015, Nature nanotechnology.

[9]  Yongbo Yuan,et al.  Photovoltaic Switching Mechanism in Lateral Structure Hybrid Perovskite Solar Cells , 2015 .

[10]  H. Bolink,et al.  Trap‐Assisted Non‐Radiative Recombination in Organic–Inorganic Perovskite Solar Cells , 2015, Advanced materials.

[11]  A. Zaban,et al.  Photoinduced Reversible Structural Transformations in Free-Standing CH3NH3PbI3 Perovskite Films. , 2015, The journal of physical chemistry letters.

[12]  F. Fabregat‐Santiago,et al.  Surface Polarization Model for the Dynamic Hysteresis of Perovskite Solar Cells. , 2017, The journal of physical chemistry letters.

[13]  J. Bisquert,et al.  Defect migration in methylammonium lead iodide and its role in perovskite solar cell operation , 2015 .

[14]  M. Green,et al.  Critical Role of Grain Boundaries for Ion Migration in Formamidinium and Methylammonium Lead Halide Perovskite Solar Cells , 2016 .

[15]  M. Green,et al.  Lessons Learnt from Spatially Resolved Electro‐ and Photoluminescence Imaging: Interfacial Delamination in CH3NH3PbI3 Planar Perovskite Solar Cells upon Illumination , 2017 .

[16]  Laura M. Herz,et al.  Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in an Organometal Trihalide Perovskite Absorber , 2013, Science.

[17]  Michael Grätzel,et al.  The Significance of Ion Conduction in a Hybrid Organic-Inorganic Lead-Iodide-Based Perovskite Photosensitizer. , 2015, Angewandte Chemie.

[18]  M. Scarpulla,et al.  Voltage-Induced Transients in Methylammonium Lead Triiodide Probed by Dynamic Photoluminescence Spectroscopy , 2016 .

[19]  M. Green,et al.  Mobile Ion Induced Slow Carrier Dynamics in Organic-Inorganic Perovskite CH₃NH₃PbBr₃. , 2016, ACS applied materials & interfaces.

[20]  Aron Walsh,et al.  Ionic transport in hybrid lead iodide perovskite solar cells , 2015, Nature Communications.

[21]  Bo Chen,et al.  Impact of Capacitive Effect and Ion Migration on the Hysteretic Behavior of Perovskite Solar Cells. , 2015, The journal of physical chemistry letters.

[22]  Haibo Zeng,et al.  Photon Driven Transformation of Cesium Lead Halide Perovskites from Few‐Monolayer Nanoplatelets to Bulk Phase , 2016, Advanced materials.

[23]  Xiaofan Deng,et al.  Electric field induced reversible and irreversible photoluminescence responses in methylammonium lead iodide perovskite , 2016 .

[24]  J. Grey,et al.  Modulating charge recombination and structural dynamics in isolated organometal halide perovskite crystals by external electric fields. , 2015, The journal of physical chemistry letters.

[25]  H. Snaith,et al.  Light-induced annihilation of Frenkel defects in organo-lead halide perovskites , 2016 .

[26]  Antonio Guerrero,et al.  Origins and mechanisms of hysteresis in organometal halide perovskites , 2017, Journal of physics. Condensed matter : an Institute of Physics journal.

[27]  Sang Il Seok,et al.  High-performance photovoltaic perovskite layers fabricated through intramolecular exchange , 2015, Science.

[28]  Y. Qi,et al.  Accelerated degradation of methylammonium lead iodide perovskites induced by exposure to iodine vapour , 2016, Nature Energy.

[29]  Yasuhiro Yamada,et al.  Photocarrier recombination dynamics in perovskite CH3NH3PbI3 for solar cell applications. , 2014, Journal of the American Chemical Society.

[30]  U. Paik,et al.  Germanium coating boosts lithium uptake in Si nanotube battery anodes. , 2014, Physical chemistry chemical physics : PCCP.

[31]  Jinsong Huang,et al.  Grain boundary dominated ion migration in polycrystalline organic–inorganic halide perovskite films , 2016 .

[32]  N. Wang,et al.  Interfacial Control Toward Efficient and Low‐Voltage Perovskite Light‐Emitting Diodes , 2015, Advanced materials.

[33]  H. Zeng,et al.  Strong covalency-induced recombination centers in perovskite solar cell material CH3NH3PbI3. , 2014, Journal of the American Chemical Society.

[34]  Angshuman Nag,et al.  Band Edge Energies and Excitonic Transition Probabilities of Colloidal CsPbX3 (X = Cl, Br, I) Perovskite Nanocrystals , 2016 .

[35]  H. Queisser,et al.  Detailed Balance Limit of Efficiency of p‐n Junction Solar Cells , 1961 .

[36]  J. Bisquert,et al.  Ionic Reactivity at Contacts and Aging of Methylammonium Lead Triiodide Perovskite Solar Cells , 2016 .

[37]  Jinsong Huang,et al.  Ultrafast ion migration in hybrid perovskite polycrystalline thin films under light and suppression in single crystals. , 2016, Physical chemistry chemical physics : PCCP.

[38]  Laura M. Herz,et al.  Charge-Carrier Dynamics in Organic-Inorganic Metal Halide Perovskites. , 2016, Annual review of physical chemistry.

[39]  M. S. Mattsson,et al.  Cation intercalation in sputter-deposited W oxide films , 1998 .

[40]  Eli Yablonovitch,et al.  Strong Internal and External Luminescence as Solar Cells Approach the Shockley–Queisser Limit , 2012, IEEE Journal of Photovoltaics.

[41]  Juan Bisquert,et al.  Nanostructured Energy Devices: Equilibrium Concepts and Kinetics , 2014 .

[42]  A. Köhler,et al.  Iodine Migration and its Effect on Hysteresis in Perovskite Solar Cells , 2016, Advanced materials.

[43]  Luzhou Chen,et al.  The efficiency limit of CH3NH3PbI3 perovskite solar cells , 2015 .

[44]  Ting Wu,et al.  Fundamental physics behind high-efficiency organo-metal halide perovskite solar cells , 2015 .

[45]  Feng Gao,et al.  Highly Efficient Perovskite Nanocrystal Light‐Emitting Diodes Enabled by a Universal Crosslinking Method , 2016, Advanced materials.

[46]  Martin A. Green,et al.  Mobile Charge-Induced Fluorescence Intermittency in Methylammonium Lead Bromide Perovskite. , 2015, Nano letters.

[47]  R. Hildner,et al.  Stepwise decrease of fluorescence versus sequential photobleaching in a single multichromophoric system. , 2014, ACS nano.

[48]  Mohammad Khaja Nazeeruddin,et al.  Predicting the Open‐Circuit Voltage of CH3NH3PbI3 Perovskite Solar Cells Using Electroluminescence and Photovoltaic Quantum Efficiency Spectra: the Role of Radiative and Non‐Radiative Recombination , 2015 .

[49]  Oleksandr Voznyy,et al.  Materials processing routes to trap-free halide perovskites. , 2014, Nano letters.

[50]  Yanfa Yan,et al.  Unusual defect physics in CH3NH3PbI3 perovskite solar cell absorber , 2014 .

[51]  Wei Zhang,et al.  Photo-induced halide redistribution in organic–inorganic perovskite films , 2016, Nature Communications.

[52]  L. Novotný,et al.  Enhancement and quenching of single-molecule fluorescence. , 2006, Physical review letters.

[53]  Jinsong Huang,et al.  π‐Conjugated Lewis Base: Efficient Trap‐Passivation and Charge‐Extraction for Hybrid Perovskite Solar Cells , 2017, Advanced materials.

[54]  Nripan Mathews,et al.  Advancements in perovskite solar cells: photophysics behind the photovoltaics , 2014 .

[55]  H. Zeng,et al.  Quantum Dot Light‐Emitting Diodes Based on Inorganic Perovskite Cesium Lead Halides (CsPbX3) , 2015, Advanced materials.

[56]  Qingfeng Dong,et al.  Giant switchable photovoltaic effect in organometal trihalide perovskite devices. , 2015, Nature materials.

[57]  D. Ginger,et al.  Impact of microstructure on local carrier lifetime in perovskite solar cells , 2015, Science.

[58]  G. Garcia‐Belmonte,et al.  Ionic charging by local imbalance at interfaces in hybrid lead halide perovskites , 2016 .

[59]  A. Köhler,et al.  Impact of Structural Dynamics on the Optical Properties of Methylammonium Lead Iodide Perovskites , 2017 .

[60]  N. Zhao,et al.  Native Defect‐Induced Hysteresis Behavior in Organolead Iodide Perovskite Solar Cells , 2016 .

[61]  Felix Deschler,et al.  Bright light-emitting diodes based on organometal halide perovskite. , 2014, Nature nanotechnology.

[62]  P. Delugas,et al.  Radiative Recombination and Photoconversion of Methylammonium Lead Iodide Perovskite by First Principles: Properties of an Inorganic Semiconductor within a Hybrid Body , 2014 .

[63]  M. Loi,et al.  Photoluminescence Enhancement in Formamidinium Lead Iodide Thin Films , 2016 .

[64]  Juan Bisquert,et al.  Slow Dynamic Processes in Lead Halide Perovskite Solar Cells. Characteristic Times and Hysteresis. , 2014, The journal of physical chemistry letters.

[65]  Nakita K. Noel,et al.  Enhanced photoluminescence and solar cell performance via Lewis base passivation of organic-inorganic lead halide perovskites. , 2014, ACS nano.

[66]  A. Efros,et al.  Random Telegraph Signal in the Photoluminescence Intensity of a Single Quantum Dot , 1997 .

[67]  R. Hildner,et al.  Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films , 2016, Molecules.

[68]  S. Meloni,et al.  Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells , 2016, Nature Communications.

[69]  Yongbo Yuan,et al.  Ion Migration in Organometal Trihalide Perovskite and Its Impact on Photovoltaic Efficiency and Stability. , 2016, Accounts of chemical research.

[70]  Ziv Hameiri,et al.  Photoluminescence and electroluminescence imaging of perovskite solar cells , 2015 .

[71]  Jinsong Huang,et al.  Electric‐Field‐Driven Reversible Conversion Between Methylammonium Lead Triiodide Perovskites and Lead Iodide at Elevated Temperatures , 2016 .

[72]  Sandeep Kumar Pathak,et al.  High Photoluminescence Efficiency and Optically Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors. , 2014, The journal of physical chemistry letters.