DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Direct Spectroscopic Observation of the Hole Polaron in Lead Halide Perovskites

Journal Article · · Journal of Physical Chemistry Letters

Intrinsic photophysical origin of lead halide perovskites (LHPs) succeeding in optolectronic applications still remains hotly debated. In this study, by using the ultrafast X-ray transient absorption spectroscopy, we successfully tracked the fate of photogenerated charge carriers at room temperature within the thin films of two classic LHPs, namely MAPbBr3 (MA: CH3NH3) and FAPbBr3 (FA: CH(NH2)2). We clearly observed in both thin films that the hole polaron is formed by localizing the photogenerated hole at Br 4p orbital and concurrently distorting the local structure surrounding Br atom after the photoexcitation. Furthermore, the bigger cation FA in the cavity of [PbBr6]4- octahedral framework induces larger hole polaron effect due to its p orbital hybridization into valence and conduction bands, correlating with the slower charge carrier recombination dynamics. Our direct experimental observation of the localized hole polaron in perovskites should advance the fundamental comprehension of charge carrier behavior within LHPs and their related devices.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357; 89233218CNA000001
OSTI ID:
1726211
Alternate ID(s):
OSTI ID: 1674972
Report Number(s):
LA-UR-20-24148
Journal Information:
Journal of Physical Chemistry Letters, Vol. 11, Issue 15; ISSN 1948-7185
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (55)

Maximizing and stabilizing luminescence from halide perovskites with potassium passivation journal March 2018
Perovskite light-emitting diodes with external quantum efficiency exceeding 20 per cent journal October 2018
High-efficiency solution-processed perovskite solar cells with millimeter-scale grains journal January 2015
Challenges for commercializing perovskite solar cells journal September 2018
Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency journal June 2018
Metal-halide perovskites for photovoltaic and light-emitting devices journal May 2015
Methylammonium-free, high-performance, and stable perovskite solar cells on a planar architecture journal October 2018
Lead halide perovskite nanowire lasers with low lasing thresholds and high quality factors journal April 2015
Origin of long lifetime of band-edge charge carriers in organic–inorganic lead iodide perovskites journal July 2017
Charge-Carrier Dynamics in Organic-Inorganic Metal Halide Perovskites journal May 2016
Charge-Carrier Mobilities in Metal Halide Perovskites: Fundamental Mechanisms and Limits journal June 2017
The Nature of Electron Mobility in Hybrid Perovskite CH 3 NH 3 PbI 3 journal May 2017
Charge Carriers in Hybrid Organic–Inorganic Lead Halide Perovskites Might Be Protected as Large Polarons journal November 2015
Intriguing Optoelectronic Properties of Metal Halide Perovskites journal June 2016
Low-bandgap mixed tin–lead iodide perovskite absorbers with long carrier lifetimes for all-perovskite tandem solar cells journal March 2017
Hybrid organic—inorganic perovskites: low-cost semiconductors with intriguing charge-transport properties journal January 2016
Lead halide perovskites: Crystal-liquid duality, phonon glass electron crystals, and large polaron formation journal October 2017
Large polarons in lead halide perovskites journal August 2017
Polaron Stabilization by Cooperative Lattice Distortion and Cation Rotations in Hybrid Perovskite Materials journal May 2016
Direct Experimental Evidence for Photoinduced Strong-Coupling Polarons in Organolead Halide Perovskite Nanoparticles journal November 2016
Screening in crystalline liquids protects energetic carriers in hybrid perovskites journal September 2016
Ultrafast THz Probe of Photoinduced Polarons in Lead-Halide Perovskites journal April 2019
Ultrafast correlated charge and lattice motion in a hybrid metal halide perovskite journal May 2019
Light-activated photocurrent degradation and self-healing in perovskite solar cells journal May 2016
Giant photostriction in organic–inorganic lead halide perovskites journal April 2016
From Large to Small Polarons in Lead, Tin, and Mixed Lead–Tin Halide Perovskites journal March 2019
Charge Localization, Stabilization, and Hopping in Lead Halide Perovskites: Competition between Polaron Stabilization and Cation Disorder journal July 2019
Polarons in Metal Halide Perovskites journal April 2020
Long-Lived Photoinduced Polarons in Organohalide Perovskites journal June 2017
Electron–Phonon Coupling and Polaron Mobility in Hybrid Perovskites from First Principles journal January 2018
Excited-state vibrational dynamics toward the polaron in methylammonium lead iodide perovskite journal June 2018
Photochemical Processes Revealed by X-ray Transient Absorption Spectroscopy journal November 2013
Recent advances on ultrafast X-ray spectroscopy in the chemical sciences journal January 2014
Probing the Impact of Solvation on Photoexcited Spin Crossover Complexes with High-Precision X-ray Transient Absorption Spectroscopy journal November 2017
Asynchronous Photoexcited Electronic and Structural Relaxation in Lead-Free Perovskites journal July 2019
Intensity of Optical Absorption by Excitons journal December 1957
Correlated electron–hole plasma in organometal perovskites journal September 2014
Efficient Planar Heterojunction Perovskite Solar Cells Based on Formamidinium Lead Bromide journal August 2014
Exploration of the compositional space for mixed lead halogen perovskites for high efficiency solar cells journal January 2016
Br K-Edge X-ray Absorption Near Edge Structure Analyses of Bromine Residue Carbon Compounds Using Full Multiple-Scattering Theory journal June 2005
X-ray absorption in polymers journal April 1980
Transient x-ray absorption spectroscopy of hydrated halogen atom journal February 2008
Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy journal July 2017
The Self-trapped Hole in CaF 2 journal June 1962
The electronic structure of V-centers journal January 1957
Self-trapped electrons and holes in PbBr 2 crystals journal June 2002
Unique Trapped Dimer State of the Photogenerated Hole in Hybrid Orthorhombic CH 3 NH 3 PbI 3 Perovskite: Identification, Origin, and Implications journal November 2017
H-Center and V-Center Defects in Hybrid Halide Perovskites journal November 2017
Polaron self-localization in white-light emitting hybrid perovskites journal January 2017
White-Light Emission from Layered Halide Perovskites journal February 2018
Excitonic and Polaronic Properties of 2D Hybrid Organic–Inorganic Perovskites journal January 2017
Quantifying the Composition of Methylammonium Lead Iodide Perovskite Thin Films with Infrared Spectroscopy journal August 2019
High Excitation Intensity Opens a New Trapping Channel in Organic–Inorganic Hybrid Perovskite Nanoparticles journal November 2016
Atomistic Origins of High-Performance in Hybrid Halide Perovskite Solar Cells journal April 2014
Critical Role of Organic Spacers for Bright 2D Layered Perovskites Light‐Emitting Diodes journal February 2020