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Ma X, Fang WH, Long R, Prezhdo OV. Compression of Organic Molecules Coupled with Hydrogen Bonding Extends the Charge Carrier Lifetime in BA 2SnI 4. J Am Chem Soc 2024; 146:16314-16323. [PMID: 38812460 DOI: 10.1021/jacs.4c05191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Two-dimensional (2D) metal halide perovskites, such as BA2SnI4 (BA═CH3(CH2)3NH3), exhibit an enhanced charge carrier lifetime in experiments under strain. Experiments suggest that significant compression of the BA molecule, rather than of the inorganic lattice, contributes to this enhancement. To elucidate the underlying physical mechanism, we apply a moderate compressive strain to the entire system and subsequently introduce significant compression to the BA molecules. We then perform ab initio nonadiabatic molecular dynamics simulations of nonradiative electron-hole recombination. We observe that the overall lattice compression reduces atomic motions and decreases nonadiabatic coupling, thereby delaying electron-hole recombination. Additionally, compression of the BA molecules enhances hydrogen bonding between the BA molecules and iodine atoms, which lengthens the Sn-I bonds, distorts the [SnI6]4- octahedra, and suppresses atomic motions further, thus reducing nonadiabatic coupling. Also, the elongated Sn-I bonds and weakened antibonding interactions increase the band gap. Altogether, the compression delays the nonradiative electron-hole recombination by more than a factor of 3. Our simulations provide new and valuable physical insights into how compressive strain, accommodated primarily by the organic ligands, positively influences the optoelectronic properties of 2D layered halide perovskites, offering a promising pathway for further performance improvements.
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Affiliation(s)
- Xinbo Ma
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
| | - Oleg V Prezhdo
- University of Southern California, Los Angeles, California 90007, United States
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2
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Qiao L, Guo M, Long R. Unveiling the Dual Role of Humidity: The Interplay with Defects Manipulating the Charge Carrier Lifetime in Metal Halide Perovskites. J Phys Chem Lett 2024; 15:1546-1552. [PMID: 38299495 DOI: 10.1021/acs.jpclett.3c03610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Humidity has exhibited experimentally either beneficial or detrimental effects on the charge carrier lifetime of CH3NH3PbI3 perovskites, leaving the mechanism unresolved. By using ab initio nonadiabatic molecular dynamics simulations, we unveil the dual role of humidity stemming from the complex interplay between water and defects. Beneficially, water passivates iodine vacancies (VI) or grain boundaries (GBs), mitigating electron trapping by reducing nonadiabatic coupling and delaying charge recombination. However, when VI and GBs coexist, water molecules make the two unsaturated lead atoms approach closer and exacerbate electron trapping by deepening the Pb-dimer electron trap that was created by the VI defect, shortening the carrier lifetime to half of pristine CH3NH3PbI3. The study uncovers the origin of the positive and negative effects of humidity on the charge carrier lifetime of perovskites and offers strategies for improving perovskite devices, particularly by avoiding simultaneous point defects and GBs.
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Affiliation(s)
- Lu Qiao
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
| | - Meng Guo
- Shandong Computer Science Center (National Supercomputing Center in Jinan), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250013, P. R. China
- Jinan Institute of Supercomputing Technology, Jinan, Shandong 250103, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
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Ma X, Long R. The sp 3 Defect Decreases Charge Carrier Lifetime in (8,3) Single-Walled Carbon Nanotubes. J Phys Chem Lett 2023; 14:10242-10248. [PMID: 37937588 DOI: 10.1021/acs.jpclett.3c02923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
A recent experimental approach introduces sp3 defects into single-walled carbon nanotubes (SWNTs) through controlled functionalization with guanine, resulting in a decrease in charge carrier lifetime. However, the physical mechanism behind this phenomenon remains unclear. We employ nonadiabatic molecular dynamics to systematically model the nonradiative recombination process of electron-hole pairs in SWNTs with sp3 defects generated by a guanine molecule. We demonstrate that the introduction of sp3 defects creates an overlapping channel between the highest occupied (HOMO) and lowest unoccupied molecular orbital (LUMO), significantly enhancing the nonadiabatic (NA) coupling and leading to a 4.7-fold acceleration in charge carrier recombination compared to defect-free SWNTs. The charge carrier recombination slows significantly at a lower temperature (50 K) due to the weakening of the NA coupling. Our results rationalize the accelerated recombination of charge carriers in SWNTs with sp3 defects in experiments and contribute to a deeper understanding of the carrier dynamics in SWNTs.
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Affiliation(s)
- Xinbo Ma
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P. R. China
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Lu H, Long R. Spin-Orbit Coupling Notably Retards Non-radiative Electron-Hole Recombination in Methylammonium Lead Triiodide Perovskites. J Phys Chem Lett 2023; 14:2715-2721. [PMID: 36892969 DOI: 10.1021/acs.jpclett.3c00473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The giant spin-orbit coupling (SOC) of a heavy lead element significantly extends charge carrier lifetimes of lead halide perovskites (LHPs). The physical mechanism remains unclear and requires a quantum dynamics perspective. Taking methylammonium lead iodide (MAPbI3) as a prototypical system and using non-adiabatic molecular dynamics combined with 1/2 electron correction, we show that SOC notably reduces the non-radiative electron-hole (e-h) recombination by decreasing the non-adiabatic coupling (NAC) primarily as a result of SOC decreasing the e-h wave function overlap by reshaping the electron and hole wave functions. Second, SOC causes spin mismatch subject to spin-mixed states, which further decreases NAC. The charge carrier lifetime is about 3-fold longer in the present of SOC relative to the absence of SOC. Our study generates the fundamental understanding of SOC minimizing non-radiative charge and energy losses in LHPs.
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Affiliation(s)
- Haoran Lu
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Run Long
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
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Shi R, Guo M, Long R. Improved Defect Tolerance and Charge Carrier Lifetime in Tin-Lead Mixed Perovskites: Ab Initio Quantum Dynamics. J Phys Chem Lett 2023; 14:499-507. [PMID: 36625793 DOI: 10.1021/acs.jpclett.2c03649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Simulations by nonadiabatic (NA) molecular dynamics demonstrate that mixing tin with lead in CH3NH3PbI3 can passivate the midgap state created by an interstitial iodine (Ii) via the imposed compressive strain and upshifted valence band maximum, reduce NA coupling by decreasing electron-hole wave functions overlap, and shortens pure-dephasing time by introducing high-frequency phonon modes. Thus, the charge carrier lifetime extends to 3.6 ns due to the significantly reduced nonradiative electron-hole recombination, which is an order of magnitude longer than the Ii-containing CH3NH3PbI3, over 2.5 times longer than the pristine CH3NH3PbI3 (1.4 ns), and even 1.7 times longer than the tin-lead mixed perovskite without the Ii defects (2.1 ns). Tin-lead alloying simultaneously increases the Ii defect formation energy to 0.402 eV from 0.179 eV in CH3NH3PbI3, which effectively enhances defect tolerance by reducing the defect concentration. The study reveals the factors controlling the enhanced performance of tin-lead mixed perovskite solar cells.
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Affiliation(s)
- Ran Shi
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
| | - Meng Guo
- Shandong Computer Science Center (National Supercomputer Centre in Jinan), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250013, P. R. China
- Jinan Institute of Supercomputing Technology, Jinan, Shandong 250103, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
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Shi R, Fang Q, Vasenko AS, Long R, Fang WH, Prezhdo OV. Structural Disorder in Higher-Temperature Phases Increases Charge Carrier Lifetimes in Metal Halide Perovskites. J Am Chem Soc 2022; 144:19137-19149. [PMID: 36206144 DOI: 10.1021/jacs.2c08627] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solar cells and optoelectronic devices are exposed to heat that degrades performance. Therefore, elucidating temperature-dependent charge carrier dynamics is essential for device optimization. Charge carrier lifetimes decrease with temperature in conventional semiconductors. The opposite, anomalous trend is observed in some experiments performed with MAPbI3 (MA = CH3NH3+) and other metal halide perovskites. Using ab initio quantum dynamics simulation, we establish the atomic mechanisms responsible for nonradiative electron-hole recombination in orthorhombic-, tetragonal-, and cubic MAPbI3. We demonstrate that structural disorder arising from the phase transitions is as important as the disorder due to heating in the same phase. The carrier lifetimes grow both with increasing temperature in the same phase and upon transition to the higher-temperature phases. The increased lifetime is rationalized by structural disorder that induces partial charge localization, decreases nonadiabatic coupling, and shortens quantum coherence. Inelastic and elastic electron-vibrational interactions exhibit opposite dependence on temperature and phase. The partial disorder and localization arise from thermal motions of both the inorganic lattice and the organic cations and depend significantly on the phase. The structural deformations induced by thermal fluctuations and phase transitions are on the same order as deformations induced by defects, and hence, thermal disorder plays a very important role. Since charge localization increases carrier lifetimes but inhibits transport, an optimal regime maximizing carrier diffusion can be designed, depending on phase, temperature, material morphology, and device architecture. The atomistic mechanisms responsible for the enhanced carrier lifetimes at elevated temperatures provide guidelines for the design of improved solar energy and optoelectronic materials.
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Affiliation(s)
- Ran Shi
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Qiu Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | | | - Run Long
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Oleg V Prezhdo
- Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California90089, United States
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Lu H, Fang WH, Long R. Collective Motion Improves the Stability and Charge Carrier Lifetime of Metal Halide Perovskites: A Phonon-Resolved Nonadiabatic Molecular Dynamics Study. J Phys Chem Lett 2022; 13:3016-3022. [PMID: 35348332 DOI: 10.1021/acs.jpclett.2c00532] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
By implementing a novel algorithm that realizes the constraints of certain normal modes of interest and using nonadiabatic molecular dynamics for the CsPbBr3, we explicitly demonstrate for the first time that the collective motion between the Cs atom and inorganic octahedra facilitates to delay the nonradiative recombination of negative and positive charges. The Cs atoms can instantaneously respond to the motion of Pb and Br atoms during normal molecular dynamics, maintain the perovskite structure, and homogenize the structural distortion caused by thermal fluctuations, thus decreasing nonadiabatic coupling and charge recombination. In contrast, the perovskite becomes unstable because geometry distortion is strongly localized when the normal modes of Cs atoms are constrained, which increases the nonadiabatic coupling and accelerates charge recombination. The study emphasizes the important role of correlated motion on the stability and charge-phonon dynamics in metal halide perovskites.
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Affiliation(s)
- Haoran Lu
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
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Dai D, Shi R, Long R. Improving Lattice Rigidity and Charge Carrier Lifetime by Engineering Spacer Cation of Ruddlesden-Popper Perovskites: A Time-Domain Ab Initio Study. J Phys Chem Lett 2022; 13:2718-2724. [PMID: 35311293 DOI: 10.1021/acs.jpclett.2c00085] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
First-principles quantum dynamics calculations show that charge carrier lifetimes, charge transport, and lattice stability are notably improved when BA (CH3(CH2)3NH3+) in BA2PbI4 is replaced with MTEA (CH3(CH2)2SNH3+). By suppressing atomic fluctuations, MTEA enhances the lattice stiffness and inhibits loss of coherence due to the S-S interaction. By delocalizing hole wave functions on the MTEA, particularly on the S atoms, while maintaining the electron wave functions largely unchanged compared to the BA2PbI4, MTEA serves to enhance charge transport and NA coupling while narrowing the bandgap by 0.18 eV. Overall, MTEA decreases NA coupling due to slow atomic motions against a large overlap of electron-hole wave functions, which suppresses nonradiative electron-hole recombination and prolongs carrier lifetime twice longer compared with BA2PbI4. This simulation presents a rational route to make high performance two-dimensional perovskite solar cells.
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Affiliation(s)
- Dandan Dai
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China
| | - Ran Shi
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China
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Zhao X, Lu H, Fang WH, Long R. Correlated organic-inorganic motion enhances stability and charge carrier lifetime in mixed halide perovskites. NANOSCALE 2022; 14:4644-4653. [PMID: 35262126 DOI: 10.1039/d1nr07732e] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Organic cations are believed to have little influence on the charge carrier lifetime in hybrid organic-inorganic perovskites. Experiments defy this expectation. We consider formamidinium lead iodide (FAPbI3) doping with and without Br as two prototypical systems, and perform ab initio time-domain nonadiabatic (NA) molecular dynamics simulations to investigate nonradiative electron-hole recombination. The simulations demonstrate that correlated organic-inorganic motion stabilizes the lattice and inhibits nonradiative charge recombination in FAPbI3 upon Br doping. Br doping suppresses the rotation of FA and the vibrations of both organic and inorganic components, and leads to hole localization and the extent of localization is enhanced upon thermal impact, notably reducing the NA coupling by decreasing the overlap between the electron and hole wave functions. Doping also slightly increases the bandgap for further decreasing NA coupling and enhances the open-circuit voltage of perovskite solar cells. The small NA coupling and large bandgap beat the slow coherence loss, delaying electron-hole recombination and extending the charge carrier lifetime to 1.5 ns in Br-doped FAPbI3, which is on the order of 1.1 ns in pristine FAPbI3. The obtained time scales are in good agreement with experiments. Multiple phonon modes, including those of both the inorganic and organic components, couple to the electronic subsystem and accommodate the excess electronic energy lost during nonradiative charge recombination. The study reveals the unexpected atomistic mechanisms for the reduction of electron-hole recombination upon Br doping, rationalizes the experiments, and advances our understanding of the excited-state dynamics of perovskite solar cells.
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Affiliation(s)
- Xi Zhao
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China.
| | - Haoran Lu
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China.
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China.
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China.
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10
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Ab initio Nonadiabatic Dynamics of Semiconductor Nanomaterials via Surface Hopping Method. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2111247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Zhu Y, Long R. Density Functional Theory Half-Electron Self-Energy Correction for Fast and Accurate Nonadiabatic Molecular Dynamics. J Phys Chem Lett 2021; 12:10886-10892. [PMID: 34730966 DOI: 10.1021/acs.jpclett.1c03077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The nonadiabatic (NA) process is crucial to photochemistry and photophysics and requires an atomistic understanding. However, conventional NA molecular dynamics (MD) for condensed-phase materials on the nanoscale are generally limited to the semilocal exchange-correlation functional, which suffers from the bandgap and thus NA coupling (NAC) problems. We consider TiO2 and a black phosphorus monolayer as two prototypical systems, perform NA-MD simulations of nonradiative electron-hole recombination, and demonstrate for the first time that density functional theory (DFT) half-electron self-energy correction can reproduce the bandgap, effective masses of carriers, luminescence line widths, NAC, and excited-state lifetimes of the two systems at the hybrid functional level while the computational cost remains at that of the Predew-Burke-Ernzerhof functional. Our study indicates that the DFT-1/2 method can greatly accelerate NA-MD simulations while maintaining the accuracy of the hybrid functional, providing an advantage for studying photoexcitation dynamics for large-scale condensed-phase materials.
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Affiliation(s)
- Yonghao Zhu
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
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