Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Flash Formation of I-Rich Clusters during Multistage Halide Segregation Studied in MAPbI1.5Br1.5

Journal Article · · Journal of Physical Chemistry. C
 [1];  [1];  [2];  [1]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis; Univ. of California, Berkeley, CA (United States)

Wide band gap mixed halide perovskites such as MAPb(I1–xBrx)3 sparked great research interest because of their outstanding optoelectronic properties, ease of fabrication, and band gap tunability. Their application thus far is however limited by light-induced halide segregation in which microscopic clusters with a high iodide content are formed and act as recombination centers. The key mechanism(s) underlying this halide segregation process are still debated. Here, we present a study on the photoluminescence evolution in MAPb(I1.5Br1.5) perovskites with varying microstructures under constant illumination at room temperature and at elevated temperature. Our findings reveal a more complicated picture of the segregation mechanism occurring in three stages instead of two as commonly reported. The process starts with a flash formation of I-rich domains. Following is a rapid blue shift before the gradual and typically observed red shift occurs. The evolution of the three stages is fully reversible in the dark and is also present at elevated temperatures (50 °C). We explain the existence of multiple stages during light-induced halide segregation by natural compositional fluctuations of the halides and the formation of halide clusters with a dynamically changing distribution in I–Br content. The variation in the I–Br ratio depends on the grain size and film heterogeneity. Overall, these findings add further details in the quest of unraveling the underlying segregation mechanism(s), which need to be identified to stabilize halides in wide band gap perovskites.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES), Chemical Sciences, Geosciences & Biosciences Division
Grant/Contract Number:
AC02-05CH11231; SC0004993
OSTI ID:
1725810
Journal Information:
Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 45 Vol. 124; ISSN 1932-7447
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (54)

Composition-Tuned Wide Bandgap Perovskites: From Grain Engineering to Stability and Performance Improvement journal July 2018
Unique Properties of Halide Perovskites as Possible Origins of the Superior Solar Cell Performance journal May 2014
Unbroken Perovskite: Interplay of Morphology, Electro-optical Properties, and Ionic Movement journal April 2016
Perovskites for Light Emission journal August 2018
A Highly Emissive Surface Layer in Mixed‐Halide Multication Perovskites journal September 2019
Stabilized Wide Bandgap MAPbBr x I 3- x Perovskite by Enhanced Grain Size and Improved Crystallinity journal December 2015
Critical Role of Grain Boundaries for Ion Migration in Formamidinium and Methylammonium Lead Halide Perovskite Solar Cells journal May 2016
Trap States, Electric Fields, and Phase Segregation in Mixed‐Halide Perovskite Photovoltaic Devices journal January 2020
The Role of Grain Boundaries on Ionic Defect Migration in Metal Halide Perovskites journal April 2020
Visualizing Phase Segregation in Mixed-Halide Perovskite Single Crystals journal January 2019
Complex evolution of photoluminescence during phase segregation of MAPb(I1-xBrx)3 mixed halide perovskite journal May 2020
Structural Origins of Light-Induced Phase Segregation in Organic-Inorganic Halide Perovskite Photovoltaic Materials journal January 2020
What Exactly Causes Light-Induced Halide Segregation in Mixed-Halide Perovskites? journal January 2020
Light induced metastable modification of optical properties in CH3NH3PbI3−xBrx perovskite films: Two-step mechanism journal July 2016
Photoinduced Anion Segregation in Mixed Halide Perovskites journal April 2020
Ion Migration in Organometal Trihalide Perovskite and Its Impact on Photovoltaic Efficiency and Stability journal January 2016
How to Make over 20% Efficient Perovskite Solar Cells in Regular ( n–i–p ) and Inverted ( p–i–n ) Architectures journal June 2018
Light-Induced Degradation of CH 3 NH 3 PbI 3 Hybrid Perovskite Thin Film journal February 2017
Cesium Lead Halide Perovskites with Improved Stability for Tandem Solar Cells journal February 2016
Thermodynamic Origin of Photoinstability in the CH 3 NH 3 Pb(I 1– x Br x ) 3 Hybrid Halide Perovskite Alloy journal March 2016
High Photoluminescence Quantum Yield in Band Gap Tunable Bromide Containing Mixed Halide Perovskites journal December 2015
Origin of Reversible Photoinduced Phase Separation in Hybrid Perovskites journal January 2017
Local Observation of Phase Segregation in Mixed-Halide Perovskite journal February 2018
Solar-Driven Metal Halide Perovskite Photocatalysis: Design, Stability, and Performance journal March 2020
Tracking Iodide and Bromide Ion Segregation in Mixed Halide Lead Perovskites during Photoirradiation journal June 2016
Defect Tolerance in Methylammonium Lead Triiodide Perovskite journal July 2016
Photoluminescence Lifetimes Exceeding 8 μs and Quantum Yields Exceeding 30% in Hybrid Perovskite Thin Films by Ligand Passivation journal July 2016
Light-Induced Phase Segregation in Halide-Perovskite Absorbers journal November 2016
Defect-Assisted Photoinduced Halide Segregation in Mixed-Halide Perovskite Thin Films journal May 2017
Shift Happens . How Halide Ion Defects Influence Photoinduced Segregation in Mixed Halide Perovskites journal June 2017
Current-Induced Phase Segregation in Mixed Halide Hybrid Perovskites and its Impact on Two-Terminal Tandem Solar Cell Design journal July 2017
Light-Induced Anion Phase Segregation in Mixed Halide Perovskites journal November 2017
Vacancy-Mediated Anion Photosegregation Kinetics in Mixed Halide Hybrid Perovskites: Coupled Kinetic Monte Carlo and Optical Measurements journal September 2018
Impact of Surfaces on Photoinduced Halide Segregation in Mixed-Halide Perovskites journal October 2018
Electronic Traps and Phase Segregation in Lead Mixed-Halide Perovskite journal November 2018
Chemical Management for Colorful, Efficient, and Stable Inorganic–Organic Hybrid Nanostructured Solar Cells journal March 2013
Hybrid organic—inorganic perovskites: low-cost semiconductors with intriguing charge-transport properties journal January 2016
Defects in perovskite-halides and their effects in solar cells journal October 2016
Low-temperature solution-processed wavelength-tunable perovskites for lasing journal March 2014
Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals journal March 2016
Rationalizing the light-induced phase separation of mixed halide organic–inorganic perovskites journal August 2017
Suppressed phase separation of mixed-halide perovskites confined in endotaxial matrices journal February 2019
Phase segregation due to ion migration in all-inorganic mixed-halide perovskite nanocrystals journal March 2019
Perovskite light-emitting diodes with external quantum efficiency exceeding 20 per cent journal October 2018
Reversible photo-induced trap formation in mixed-halide hybrid perovskites for photovoltaics journal January 2015
Grain boundary dominated ion migration in polycrystalline organic–inorganic halide perovskite films journal January 2016
A road towards 25% efficiency and beyond: perovskite tandem solar cells journal January 2016
Preventing phase segregation in mixed-halide perovskites: a perspective journal January 2020
Photoinduced phase separation in the lead halides is a polaronic effect journal June 2020
Optical Transitions in Hybrid Perovskite Solar Cells: Ellipsometry, Density Functional Theory, and Quantum Efficiency Analyses for CH 3 NH 3 PbI 3 journal January 2016
Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in an Organometal Trihalide Perovskite Absorber journal October 2013
High-efficiency solution-processed perovskite solar cells with millimeter-scale grains journal January 2015
Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon journal March 2020
Efficient, stable silicon tandem cells enabled by anion-engineered wide-bandgap perovskites journal March 2020

Similar Records

Multi stage and illumination dependent segregation in MAPb(I,Br)3
Conference · Tue Dec 31 23:00:00 EST 2019 · OSTI ID:1725803

Halide Ion Migration in Perovskite Nanocrystals and Nanostructures
Journal Article · Wed Jan 20 23:00:00 EST 2021 · Accounts of Chemical Research · OSTI ID:1774775