1
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Kambhampati P. Unraveling the excitonics of light emission from metal-halide perovskite quantum dots. NANOSCALE 2024; 16:15033-15058. [PMID: 39052235 DOI: 10.1039/d4nr01481b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Metal halide semicondictor perovskites have been under intense investigation for their promise in light absorptive applications like photovoltaics. They have more recently experienced interest for their promise in light emissive applications. A key aspect of perovskites is their glassy, ionic lattice that exhibits dynamical disorder. One possible result of this dynamical disorder is their strong coupling between electronic and lattice degrees of freedom which may confer remarkable properties for light emission such as defect tolerance. How does the system, comprised of excitons, couple to the bath, comprised of lattice modes? How does this system-bath interaction give rise to novel light emissive properties and how do these properties give insight into the nature of these materials? We review recent work from this group in which time-resolved photoluminescence spectroscopy is used to reveal such insights. Based upon a fast time resolution of 3 ps, energy resolution, and temperature dependence, a wide variety of insights are gleaned. These insights include: lattice contributions to the emission linewidths, multiexciton formation, hot carrier cooling, excitonic fine structure, single dot superradiance, and a breakdown of the Condon approximation, all due to complex structural dynamics in these materials.
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2
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De A, Bhunia S, Cai Y, Binyamin T, Etgar L, Ruhman S. Spectator Exciton Effects in Nanocrystals III: Unveiling the Stimulated Emission Cross Section in Quantum Confined CsPbBr 3 Nanocrystals. J Am Chem Soc 2024; 146:20241-20250. [PMID: 39007415 PMCID: PMC11273341 DOI: 10.1021/jacs.4c05412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/04/2024] [Accepted: 07/08/2024] [Indexed: 07/16/2024]
Abstract
Quantifying stimulated emission in semiconductor nanocrystals (NCs) remains challenging due to masking of its effects on pump-probe spectra by excited state absorption and ground state bleaching signals. The absence of this defining photophysical parameter in turn impedes assignment of band edge electronic structure in many of these important fluorophores. Here we employ a generally applicable 3-pulse ultrafast spectroscopic method coined the "Spectator Exciton" (SX) approach to measure stimulated-emission efficiency in quantum confined inorganic perovskite CsPbBr3 NCs, the band edge electronic structure of which is the subject of lively ongoing debate. Our results show that in 5-6 nm CsPbBr3 NCs, a single exciton bleaches more than half of the intense band edge absorption band, while the cross section for stimulated emission from the same state is nearly 6 times weaker. Discussion of these findings in light of several recent electronic structure models for this material proves them unable to simultaneously explain both measures, proving the importance of this new input to resolving this debate. Along with femtosecond time-resolved photoluminescence measurements on the same sample, SX results also verify that biexciton interaction energy is intensely attractive with a magnitude of ∼80 meV. In light of this observation, our previous suggestion that biexciton interaction is repulsive is reassigned to hot phonon induced slowdown of carrier relaxation leading to direct Auger recombination from an excited state. The mechanism behind the extreme slowing of carrier cooling after several stages of exciton recombination remains to be determined.
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Affiliation(s)
- Apurba De
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
| | - Soumyadip Bhunia
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
| | - Yichao Cai
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
| | - Tal Binyamin
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
| | - Lioz Etgar
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
| | - Sanford Ruhman
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem-91904, Israel
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3
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Lim JWM, Guo Y, Feng M, Cai R, Sum TC. Making and Breaking of Exciton Cooling Bottlenecks in Halide Perovskite Nanocrystals. J Am Chem Soc 2024; 146:437-449. [PMID: 38158611 DOI: 10.1021/jacs.3c09761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Harnessing quantum confinement (QC) effects in semiconductors to retard hot carrier cooling (HCC) is an attractive approach for enabling efficient hot carrier extraction to overcome the Shockley-Queisser limit. However, there is a debate about whether halide perovskite nanocrystals (PNCs) can effectively exploit these effects. To address this, we utilized pump-probe and multipulse pump-push-probe spectroscopy to investigate HCC behavior in PNCs of varying sizes and cation compositions. Our results validate the presence of an intrinsic phonon bottleneck with clear manifestations of QC effects in small CsPbBr3 PNCs exhibiting slower HCC rates compared to those of larger PNCs. However, the replacement of inorganic Cs+ with organic cations suppresses this intrinsic bottleneck. Furthermore, PNCs exhibit distinct size-dependent HCC behavior in response to changes in the cold carrier densities. We attribute this to the enhanced exciton-exciton interactions in strongly confined PNCs that facilitate Auger heating. Importantly, our findings dispel the existing controversy and provide valuable insights into design principles for engineering QC effects in PNC hot carrier applications.
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Affiliation(s)
- Jia Wei Melvin Lim
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Yuanyuan Guo
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Minjun Feng
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Rui Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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4
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Strandell D, Dirin D, Zenatti D, Nagpal P, Ghosh A, Raino G, Kovalenko MV, Kambhampati P. Enhancing Multiexcitonic Emission in Metal-Halide Perovskites by Quantum Confinement. ACS NANO 2023; 17:24910-24918. [PMID: 38079478 DOI: 10.1021/acsnano.3c06497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Semiconductor metal halide perovskite nanocrystals have been under intense investigation for their promise in a variety of optoelectronic applications, which arises from their remarkable properties of defect tolerance and efficient light emission. Recently, quantum dot versions of perovskite nanocrystals have been available, enabling investigation of how quantum size effects control optical function and performance in these quantum dots (QD), past their well-known covalent II-VI analogues. We perform time-resolved photoluminescence (t-PL) experiments on CsPbBr3 perovskite nanocrystals spanning in diameter from 5.8 nm strongly confined quantum dots to 18 nm weakly confined quantum dots. Experiments are performed with sufficient time resolution of 3 ps to observe the interaction energies and recombination kinetics from excitons to multiexcitons. Comparing the same sized QD reveals that perovskite QD have a larger radiative rate constant for emission from X than CdSe QD due to a larger oscillator strength. The multiexciton (MX) regime reveals that perovskite QD emit brightly and with more focused bandwidth than equivalent sized CdSe QD enabling more spectrally pure brightness. The MX kinetics reveals that the perovskite QD maintain efficient radiative decay, effectively competing with Auger recombination. These experiments reveal that the strongly confined QD of perovskites can be efficient multiexcitonic emitters, such as in high brightness light emitting diodes, especially in the blue.
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Affiliation(s)
- Dallas Strandell
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Dmitry Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Davide Zenatti
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Priya Nagpal
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Arnab Ghosh
- Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada
| | - Gabriele Raino
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600 Dubendorf, Switzerland
| | - Maksym V Kovalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
- Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600 Dubendorf, Switzerland
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5
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Liu Y, Li Y, Gao K, Zhu J, Wu K. Sub-Single-Exciton Optical Gain in Lead Halide Perovskite Quantum Dots Revealed by Exciton Polarization Spectroscopy. J Am Chem Soc 2023; 145:25864-25873. [PMID: 37971813 DOI: 10.1021/jacs.3c10281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Optical gain of colloidal quantum dots (QDs) is often attained in the multiexciton regime, which strongly complicates their lasing applications as the gain lifetime is limited by nonradiative Auger recombination occurring typically on the picosecond time scale. In principle, low-threshold gain can be achieved if the gain-active emission has a sizable red shift compared to the absorption. But, this mechanism has been rarely observed in typical QDs featuring small Stokes shift due to their weak electron-phonon coupling. Here, we report the observation of sub-single-exciton gain in CsPbI3 and CsPbBr3 perovskite QDs, which is unequivocally established through pinpointing the stimulated emission and biexciton absorption signatures using polarization-controlled femtosecond transient absorption spectroscopy. The soft lattice of perovskite QDs and hence strong electron-phonon coupling lead to two stimulated emission features from free and self-trapped excitons, respectively. In monodisperse QDs of varying sizes, the Stokes shift of the self-trapped exciton emission is sufficiently large to overcome the biexciton absorption loss and the inhomogeneous line width, enabling optical gain with average exciton occupancy down to <10%.
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Affiliation(s)
- Yuan Liu
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Yuxuan Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaimin Gao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingyi Zhu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Kaifeng Wu
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Carwithen BP, Hopper TR, Ge Z, Mondal N, Wang T, Mazlumian R, Zheng X, Krieg F, Montanarella F, Nedelcu G, Kroll M, Siguan MA, Frost JM, Leo K, Vaynzof Y, Bodnarchuk MI, Kovalenko MV, Bakulin AA. Confinement and Exciton Binding Energy Effects on Hot Carrier Cooling in Lead Halide Perovskite Nanomaterials. ACS NANO 2023; 17:6638-6648. [PMID: 36939330 PMCID: PMC10100565 DOI: 10.1021/acsnano.2c12373] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
The relaxation of the above-gap ("hot") carriers in lead halide perovskites (LHPs) is important for applications in photovoltaics and offers insights into carrier-carrier and carrier-phonon interactions. However, the role of quantum confinement in the hot carrier dynamics of nanosystems is still disputed. Here, we devise a single approach, ultrafast pump-push-probe spectroscopy, to study carrier cooling in six different size-controlled LHP nanomaterials. In cuboidal nanocrystals, we observe only a weak size effect on the cooling dynamics. In contrast, two-dimensional systems show suppression of the hot phonon bottleneck effect common in bulk perovskites. The proposed kinetic model describes the intrinsic and density-dependent cooling times accurately in all studied perovskite systems using only carrier-carrier, carrier-phonon, and excitonic coupling constants. This highlights the impact of exciton formation on carrier cooling and promotes dimensional confinement as a tool for engineering carrier-phonon and carrier-carrier interactions in LHP optoelectronic materials.
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Affiliation(s)
- Ben P. Carwithen
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Thomas R. Hopper
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
| | - Ziyuan Ge
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Navendu Mondal
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Tong Wang
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Rozana Mazlumian
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Xijia Zheng
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Franziska Krieg
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa−Swiss
Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Federico Montanarella
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa−Swiss
Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Georgian Nedelcu
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa−Swiss
Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, Groningen 9747AG, The Netherlands
| | - Martin Kroll
- Center
for
Advancing Electronics Dresden, Technische
Universität Dresden, 01069 Dresden, Germany
- Integrated
Center for Applied Photophysics and Photonic Materials, Technische Universität Dresden, 01187 Dresden, Germany
| | - Miguel Albaladejo Siguan
- Chair
for Emerging Electronic Technologies, Technische
Universität Dresden, 01187 Dresden, Germany
- Leibniz
Institute for Solid State and Materials Research Dresden, Technische Universität Dresden, 01069 Dresden, Germany
| | - Jarvist M. Frost
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
| | - Karl Leo
- Integrated
Center for Applied Photophysics and Photonic Materials, Technische Universität Dresden, 01187 Dresden, Germany
| | - Yana Vaynzof
- Chair
for Emerging Electronic Technologies, Technische
Universität Dresden, 01187 Dresden, Germany
- Leibniz
Institute for Solid State and Materials Research Dresden, Technische Universität Dresden, 01069 Dresden, Germany
| | - Maryna I. Bodnarchuk
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa−Swiss
Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Maksym V. Kovalenko
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa−Swiss
Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Artem A. Bakulin
- Department
of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United
Kingdom
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7
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Zhu C, Nguyen T, Boehme SC, Moskalenko A, Dirin DN, Bodnarchuk MI, Katan C, Even J, Rainò G, Kovalenko MV. Many-Body Correlations and Exciton Complexes in CsPbBr 3 Quantum Dots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208354. [PMID: 36537857 DOI: 10.1002/adma.202208354] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/25/2022] [Indexed: 06/17/2023]
Abstract
All-inorganic lead-halide perovskite (LHP) (CsPbX3 , X = Cl, Br, I) quantum dots (QDs) have emerged as a competitive platform for classical light-emitting devices (in the weak light-matter interaction regime, e.g., LEDs and laser), as well as for devices exploiting strong light-matter interaction at room temperature. Many-body interactions and quantum correlations among photogenerated exciton complexes play an essential role, for example, by determining the laser threshold, the overall brightness of LEDs, and the single-photon purity in quantum light sources. Here, by combining cryogenic single-QD photoluminescence spectroscopy with configuration-interaction (CI) calculations, the size-dependent trion and biexciton binding energies are addressed. Trion binding energies increase from 7 to 17 meV for QD sizes decreasing from 30 to 9 nm, while the biexciton binding energies increase from 15 to 30 meV, respectively. CI calculations quantitatively corroborate the experimental results and suggest that the effective dielectric constant for biexcitons slightly deviates from the one of the single excitons, potentially as a result of coupling to the lattice in the multiexciton regime. The findings here provide a deep insight into the multiexciton properties in all-inorganic LHP QDs, essential for classical and quantum optoelectronic devices.
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Affiliation(s)
- Chenglian Zhu
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Tan Nguyen
- Univ Rennes, ENSCR, CNRS, ISCR - UMR6226, Rennes, F-35000, France
| | - Simon C Boehme
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Anastasiia Moskalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Dmitry N Dirin
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Maryna I Bodnarchuk
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Claudine Katan
- Univ Rennes, ENSCR, CNRS, ISCR - UMR6226, Rennes, F-35000, France
| | - Jacky Even
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON - UMR6082, Rennes, F-35000, France
| | - Gabriele Rainò
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
| | - Maksym V Kovalenko
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, CH-8600, Switzerland
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8
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Universal scaling laws for charge-carrier interactions with quantum confinement in lead-halide perovskites. Nat Commun 2023; 14:229. [PMID: 36646706 PMCID: PMC9842747 DOI: 10.1038/s41467-023-35842-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/04/2023] [Indexed: 01/17/2023] Open
Abstract
Lead halide perovskites open great prospects for optoelectronics and a wealth of potential applications in quantum optical and spin-based technologies. Precise knowledge of the fundamental optical and spin properties of charge-carrier complexes at the origin of their luminescence is crucial in view of the development of these applications. On nearly bulk Cesium-Lead-Bromide single perovskite nanocrystals, which are the test bench materials for next-generation devices as well as theoretical modeling, we perform low temperature magneto-optical spectroscopy to reveal their entire band-edge exciton fine structure and charge-complex binding energies. We demonstrate that the ground exciton state is dark and lays several millielectronvolts below the lowest bright exciton sublevels, which settles the debate on the bright-dark exciton level ordering in these materials. More importantly, combining these results with spectroscopic measurements on various perovskite nanocrystal compounds, we show evidence for universal scaling laws relating the exciton fine structure splitting, the trion and biexciton binding energies to the band-edge exciton energy in lead-halide perovskite nanostructures, regardless of their chemical composition. These scaling laws solely based on quantum confinement effects and dimensionless energies offer a general predictive picture for the interaction energies within charge-carrier complexes photo-generated in these emerging semiconductor nanostructures.
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9
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Barfüßer A, Rieger S, Dey A, Tosun A, Akkerman QA, Debnath T, Feldmann J. Confined Excitons in Spherical-Like Halide Perovskite Quantum Dots. NANO LETTERS 2022; 22:8810-8817. [PMID: 36251337 DOI: 10.1021/acs.nanolett.2c02223] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Quantum dots (QDs) offer unique physical properties and novel application possibilities like single-photon emitters for quantum technologies. While strongly confined III-V and II-VI QDs have been studied extensively, their complex valence band structure often limits clear observations of individual transitions. In recently emerged lead-halide perovskites, band degeneracies are absent around the bandgap reducing the complexity of optical spectra. We show that for spherical-like CsPbBr3 QDs with diameters >6 nm, excitons confine with respect to their center-of-mass motion leading to well-pronounced resonances in their absorption spectra. Optical pumping of the lowest-confined exciton with femtosecond laser pulses not only bleaches all excitons but also reveals a series of distinct induced absorption resonances which we attribute to exciton-to-biexciton transitions and are red-shifted by the biexciton binding energy (∼40 meV). The temporal dynamics of the bleached excitons further support our exciton confinement model. Our study provides the first insight into confined excitons in CsPbBr3 QDs and gives a detailed understanding of their linear and nonlinear optical spectra.
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Affiliation(s)
- Anja Barfüßer
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Sebastian Rieger
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Amrita Dey
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Ahmet Tosun
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Quinten A Akkerman
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Tushar Debnath
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
| | - Jochen Feldmann
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstrasse 10, 80539Munich, Germany
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10
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Li Y, Han Y, Liang W, Zhang B, Li Y, Liu Y, Yang Y, Wu K, Zhu J. Excitonic Bloch-Siegert shift in CsPbI 3 perovskite quantum dots. Nat Commun 2022; 13:5559. [PMID: 36138041 PMCID: PMC9500032 DOI: 10.1038/s41467-022-33314-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 09/13/2022] [Indexed: 11/09/2022] Open
Abstract
Coherent interaction between matter and light field induces both optical Stark effect and Bloch-Siegert shift. Observing the latter has been historically challenging, because it is weak and is often accompanied by a much stronger Stark shift. Herein, by controlling the light helicity, we can largely restrict these two effects to different spin-transitions in CsPbI3 perovskite quantum dots, achieving room-temperature Bloch-Siegert shift as strong as 4 meV with near-infrared pulses. The ratio between the Bloch-Siegert and optical Stark shifts is however systematically higher than the prediction by the non-interacting, quasi-particle model. With a model that explicitly accounts for excitonic effects, we quantitatively reproduce the experimental observations. This model depicts a unified physical picture of the optical Stark effect, biexcitonic optical Stark effect and Bloch-Siegert shift in low-dimensional materials displaying strong many-body interactions, forming the basis for the implementation of these effects to information processing, optical modulation and Floquet engineering.
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Affiliation(s)
- Yuxuan Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yaoyao Han
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenfei Liang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China
| | - Boyu Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.,Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Art and Science, Xiangyang, 441053, Hubei, China
| | - Yulu Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China
| | - Yuan Liu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.,University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yupeng Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Jingyi Zhu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.
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11
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Saikia S, Joshi A, Arfin H, Badola S, Saha S, Nag A. Sb
3+
–Er
3+
‐Codoped Cs
2
NaInCl
6
for Emitting Blue and Short‐Wave Infrared Radiation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sajid Saikia
- Department of Chemistry Indian Institute of Science Education and Research (IISER) Pune 411008 India
| | - Aprajita Joshi
- Department of Physics Indian Institute of Science Education and Research Bhopal 462066 India
| | - Habibul Arfin
- Department of Chemistry Indian Institute of Science Education and Research (IISER) Pune 411008 India
| | - Shalini Badola
- Department of Physics Indian Institute of Science Education and Research Bhopal 462066 India
| | - Surajit Saha
- Department of Physics Indian Institute of Science Education and Research Bhopal 462066 India
| | - Angshuman Nag
- Department of Chemistry Indian Institute of Science Education and Research (IISER) Pune 411008 India
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12
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Saikia S, Joshi A, Arfin H, Badola S, Saha S, Nag A. Sb3+-Er3+-Codoped Cs2NaInCl6 for Emitting Blue and Short-Wave Infrared Radiation. Angew Chem Int Ed Engl 2022; 61:e202201628. [PMID: 35403771 DOI: 10.1002/anie.202201628] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Indexed: 11/06/2022]
Abstract
Cs 2 NaInCl 6 double perovskite is stable, environmentally benign, and can be prepared easily. But it has high band gap (5.1 eV), and therefore, does not show optical and optoelectronic properties in the visible and short-wave infrared (SWIR) region. Here we introduce such functionalities in Cs 2 NaInCl 6 by codoping Sb 3+ ( s -electron doping) and Er 3+ ( f -electron doping). Sb 3+ doping introduces optically allowed 5 s 2 → 5 s 1 5 p 1 electronic absorption at the sub band gap level, which then emit blue light with ~93% photoluminescence quantum yield. On the other hand, f-f electronic absorption of Er 3+ is parity forbidden. Codoping Sb 3+ -Er 3+ , leads to transfer of excitation energy from Sb 3+ to Er 3+ , yielding SWIR emission at 1540 nm that falls in the optical fiber communication region. Temperature (6 to 300 K) dependent photoluminescence measurements elucidate the excitation mechanism in the codoped Cs 2 NaInCl 6 . Further, we have fabricated phosphor converted light emitting diode (pc-LED) by coating the codoped sample on commercial ultraviolet LED chips. The pc-LED emit stable blue and SWIR radiation over prolonged operation (over 84 hours) at 5.1 V.
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Affiliation(s)
- Sajid Saikia
- Indian Institute of Science Education and Research Pune, Chemistry, INDIA
| | - Aprajita Joshi
- Indian Institute of Science Education and Research Bhopal, Physics, INDIA
| | - Habibul Arfin
- Indian Institute of Science Education and Research Pune, Chemistry, INDIA
| | - Shalini Badola
- Indian Institute of Science Education and Research Bhopal, Physics, INDIA
| | - Surajit Saha
- Indian Institute of Science Education and Research Bhopal, Physics, INDIA
| | - Angshuman Nag
- Indian Institute of Science Education and Research (IISER) Pune, Chemistry, Dr. Homi Bhabha Road, 411008, Pune, INDIA
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13
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Park Y, Obliger A, Limmer DT. Nonlocal Screening Dictates the Radiative Lifetimes of Excitations in Lead Halide Perovskites. NANO LETTERS 2022; 22:2398-2404. [PMID: 35234469 DOI: 10.1021/acs.nanolett.2c00077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We use path integral molecular dynamics simulations and theory to elucidate the interactions between charge carriers, as mediated by a lead halide perovskite lattice. We find that the charge-lattice coupling of MAPbI3 results in a repulsive interaction between electrons and holes at intermediate distances. The effective interaction is understood using a Gaussian field theory, whereby the underlying soft, polar lattice contributes a nonlocal screening between quasiparticles. Path integral calculations of this nonlocal screening model are used to rationalize the small exciton binding energy and low radiative recombination rate observed experimentally and are compared to traditional Wannier-Mott and Fröhlich models, which fail to do so. These results clarify the origin of the high power conversion efficiencies in lead halide perovskites. Emergent repulsive electron-hole interactions provide a design principle for optimizing soft, polar semiconductors.
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Affiliation(s)
- Yoonjae Park
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Amael Obliger
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - David T Limmer
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
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14
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Lubin G, Yaniv G, Kazes M, Ulku AC, Antolovic IM, Burri S, Bruschini C, Charbon E, Yallapragada VJ, Oron D. Resolving the Controversy in Biexciton Binding Energy of Cesium Lead Halide Perovskite Nanocrystals through Heralded Single-Particle Spectroscopy. ACS NANO 2021; 15:19581-19587. [PMID: 34846120 PMCID: PMC8717625 DOI: 10.1021/acsnano.1c06624] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Understanding exciton-exciton interaction in multiply excited nanocrystals is crucial to their utilization as functional materials. Yet, for lead halide perovskite nanocrystals, which are promising candidates for nanocrystal-based technologies, numerous contradicting values have been reported for the strength and sign of their exciton-exciton interaction. In this work, we unambiguously determine the biexciton binding energy in single cesium lead halide perovskite nanocrystals at room temperature. This is enabled by the recently introduced single-photon avalanche diode array spectrometer, capable of temporally isolating biexciton-exciton emission cascades while retaining spectral resolution. We demonstrate that CsPbBr3 nanocrystals feature an attractive exciton-exciton interaction, with a mean biexciton binding energy of 10 meV. For CsPbI3 nanocrystals, we observe a mean biexciton binding energy that is close to zero, and individual nanocrystals show either weakly attractive or weakly repulsive exciton-exciton interaction. We further show that, within ensembles of both materials, single-nanocrystal biexciton binding energies are correlated with the degree of charge-carrier confinement.
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Affiliation(s)
- Gur Lubin
- Department
of Physics of Complex Systems, Weizmann
Institute of Science, Rehovot 7610001, Israel
| | - Gili Yaniv
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Miri Kazes
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Arin Can Ulku
- School
of Engineering, École polytechnique
fédérale de Lausanne (EPFL), Neuchâtel 2002, Switzerland
| | - Ivan Michel Antolovic
- School
of Engineering, École polytechnique
fédérale de Lausanne (EPFL), Neuchâtel 2002, Switzerland
| | - Samuel Burri
- School
of Engineering, École polytechnique
fédérale de Lausanne (EPFL), Neuchâtel 2002, Switzerland
| | - Claudio Bruschini
- School
of Engineering, École polytechnique
fédérale de Lausanne (EPFL), Neuchâtel 2002, Switzerland
| | - Edoardo Charbon
- School
of Engineering, École polytechnique
fédérale de Lausanne (EPFL), Neuchâtel 2002, Switzerland
| | - Venkata Jayasurya Yallapragada
- Department
of Physics of Complex Systems, Weizmann
Institute of Science, Rehovot 7610001, Israel
- Department
of Physics, Indian Institute of Technology
Kanpur, Kanpur 208016, India
- (V.J.Y.)
| | - Dan Oron
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
- (D.O.)
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15
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Ruhman S. Solving Quantum-Dot Excitonic Riddles with Absolute Pump-Probe Spectroscopy. J Phys Chem Lett 2021; 12:9336-9343. [PMID: 34549584 DOI: 10.1021/acs.jpclett.1c02408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Absolute absorption changes in molecular flash photolysis experiments are routinely translated into molar extinction coefficients and oscillator strengths of reactive intermediates. These direct quantum chemical investigation and allow precise concentration readings in later experiments. In this Perspective we show how a similar approach can deliver crucial information for interpreting transient absorption spectra in colloidal semiconductor quantum dots. The intrinsic complexity of such samples stemming from the inhomogeneity of particle size, shape, and surface chemistry poses unique challenges to mechanistic assignment of ultrafast pump-probe measurements. We will describe applications of this approach to elucidate the photophysics of quantum confined nanocrystals made of various semiconducting materials. These case studies demonstrate how, faced with conflicting interpretations, it has pointed in the right direction in assessing single and multiple exciton generation and relaxation, in searches for ultrafast carrier trapping and scavenging, and in tests of band edge level structure and state degeneracies.
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Affiliation(s)
- Sanford Ruhman
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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16
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Zheng X, Hopper TR, Gorodetsky A, Maimaris M, Xu W, Martin BAA, Frost JM, Bakulin AA. Multipulse Terahertz Spectroscopy Unveils Hot Polaron Photoconductivity Dynamics in Metal-Halide Perovskites. J Phys Chem Lett 2021; 12:8732-8739. [PMID: 34478291 DOI: 10.1021/acs.jpclett.1c02102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hot carriers in metal-halide perovskites (MHPs) present a foundation for understanding carrier-phonon coupling in the materials as well as the prospective development of high-performance hot carrier photovoltaics. While the carrier population dynamics during cooling have been scrutinized, the evolution of the hot carrier properties, namely mobility, remains largely unexplored. Here we introduce novel ultrafast visible pump-infrared push-terahertz probe spectroscopy to monitor the real-time conductivity dynamics of cooling carriers in methylammonium lead iodide. We find a decrease in mobility upon optically re-exciting the carriers, as expected for band transport. Surprisingly, the conductivity recovery is incommensurate with the hot carrier population dynamics measured by infrared probe and exhibits a negligible dependence on the hot carrier density. Our results reveal the importance of localized lattice heating toward the hot carrier mobility. This collective polaron-lattice phenomenon may contribute to the unusual photophysics of MHPs and should be accounted for in hot carrier devices.
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Affiliation(s)
- Xijia Zheng
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Thomas R Hopper
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Andrei Gorodetsky
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Marios Maimaris
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Weidong Xu
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Bradley A A Martin
- Department of Physics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Jarvist M Frost
- Department of Physics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Artem A Bakulin
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
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