Dipin K. Tomar, Swapnil Deshpande, Shubham Gupta, Amogh K. Ravi, Sudip Chakraborty, Pabitra K Nayak, Jyotishman Dasgupta
{"title":"Exciton-Polaron in a Quasi-One-Dimensional Chain of Hexyl-Diammonium-BiI5 Octahedra","authors":"Dipin K. Tomar, Swapnil Deshpande, Shubham Gupta, Amogh K. Ravi, Sudip Chakraborty, Pabitra K Nayak, Jyotishman Dasgupta","doi":"10.1021/acs.jpclett.4c02696","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02696","url":null,"abstract":"Lower-dimensional organic–inorganic hybrid perovskite materials promise to revolutionize the optoelectronics industry due to the tremendous possibilities of exotic control on excitonic properties driven via quantum confinement. Flexible organic cations acting as spacers and stabilizers enhance electron–phonon couplings, further amplifying the potential for modular light–matter interactions in these materials. Herein we unravel the nature of excitons in a quasi-1D chain of corner-sharing bismuth iodide octahedra with an intrinsic quantum well structure stabilized by a hexyl-diammonium cation. Using broadband femtosecond impulsive Raman spectroscopy and detailed electronic structure calculations, we directly quantify the exciton lifetime along with the electron–phonon coupling constants to fully describe the excitation as an exciton-polaron. We find ∼30 times larger electron–phonon couplings beyond the standard 2D-hybrid perovskite materials along with picosecond time-scale decoherences, thereby shedding light for the first time on the immense potential of these 1D perovskite analogues for developing novel materials for efficient light-conversion technologies.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"48 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiasong Lin, Zhen Wang, Qinghong Lin, Jiayu Sun, Xuan Guo, Yue Wang, Liangxu Lin, Yi Zhao, Yang Liu, Deli Li, Fushan Li
{"title":"PbS Quantum Dot-Based Optoelectronic Memristors toward Multi-Task Reservoir Computing","authors":"Jiasong Lin, Zhen Wang, Qinghong Lin, Jiayu Sun, Xuan Guo, Yue Wang, Liangxu Lin, Yi Zhao, Yang Liu, Deli Li, Fushan Li","doi":"10.1021/acs.jpclett.4c03350","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03350","url":null,"abstract":"The rise of big data and the internet of things has driven the demand for multimodal sensing and high-efficiency low-latency processing. Inspired by the human sensory system, we present a multifunctional optoelectronic-memristor-based reservoir computing (OM-RC) system by utilizing a CuSCN/PbS quantum dots (QDs) heterojunction. The OM-RC system exhibits volatile and nonlinear responses to electrical signals and wide-spectrum optical stimuli covering ultraviolet, visible, and near-infrared (NIR) regions, enabling multitask processing of dynamic signals. The OM-RC system accurately performs health monitoring through dynamic electroencephalogram and electrocardiogram signal analysis and achieves object and traffic trajectory recognition for intelligent driving under challenging conditions like foggy environments. By collaboratively using the NIR perception and trajectory recognition, we develop a human–computer interaction authentication system that integrates finger veins and motion behaviors of humans, significantly enhancing the security of traditional fingerprint anticounterfeiting systems. This work demonstrates the potential of QD-based optoelectronic-memristor for multitask in-sensor processing applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"14 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lu Qiao, Andrey S. Vasenko, Evgueni V. Chulkov, Run Long
{"title":"Schottky Defects Suppress Nonradiative Recombination in CH3NH3PbI3 through Charge Localization","authors":"Lu Qiao, Andrey S. Vasenko, Evgueni V. Chulkov, Run Long","doi":"10.1021/acs.jpclett.4c03313","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03313","url":null,"abstract":"Hybrid lead halide perovskites are promising materials for photovoltaic applications due to their exceptional optoelectronic properties. Here, we investigate the impact of Schottky defects─specifically PbI<sub>2</sub>(V<sub>PbI<sub>2</sub></sub>) and CH<sub>3</sub>NH<sub>3</sub>I (V<sub>MAI</sub>) vacancies─on nonradiative recombination in CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> using time-dependent density functional theory and nonadiabatic (NA) molecular dynamics. Our results reveal that Schottky defects do not alter the fundamental bandgap or introduce trap states but instead distort the surrounding lattice, localizing the hole distribution. This reduces the spatial overlap of electron and hole wave functions, weakening NA coupling and increasing intensitieis of high-intensity phonon modes that accelerate dephasing. Consequently, nonradiative recombination lifetimes extend to 2.1 and 2.6 ns for V<sub>PbI<sub>2</sub></sub> and V<sub>MAI</sub>, respectively─over double that of pristine CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>. This work demonstrates the potential of Schottky defects to enhance perovskite solar cell performance by suppressing nonradiative recombination.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"13 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pelayo Marin-Villa, Mattia Gaboardi, Boby Joseph, Frederico Alabarse, Jeff Armstrong, Kacper Drużbicki, Felix Fernandez-Alonso
{"title":"Methylammonium Lead Iodide across Physical Space: Phase Boundaries and Structural Collapse","authors":"Pelayo Marin-Villa, Mattia Gaboardi, Boby Joseph, Frederico Alabarse, Jeff Armstrong, Kacper Drużbicki, Felix Fernandez-Alonso","doi":"10.1021/acs.jpclett.4c03336","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03336","url":null,"abstract":"Hybrid perovskites exhibit complex structures and phase behavior under different thermodynamic conditions and chemical environments, the understanding of which continues to be pivotally important for tailoring their properties toward improved operational stability. To this end, we present for the first time a comprehensive neutron and synchrotron diffraction investigation over the pressure–temperature phase diagram of the paradigmatic hybrid organic–inorganic perovskite methylammonium lead iodide (MAPbI<sub>3</sub>). This ambitious experimental campaign down to cryogenic temperatures and tens of kilobars was supported by extensive <i>ab initio</i> molecular dynamics simulations validated by the experimental data, to track the structural evolution of MAPbI<sub>3</sub> under external physical stimuli at the atomic and molecular levels. These combined efforts enable us to identify the mechanisms underpinning structural phase transitions, including those exhibiting negative thermal expansion across the boundary between the cation-ordered low-temperature phase and the dynamically disordered high-pressure cubic phase. Our results bring to the fore how pronounced octahedral distortions at high pressures ultimately drive the structural collapse and amorphization of this material.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"53 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingyue Wang, Tianchen Qin, Tian Ma, Sifan You, Jia Wang, Lei Hu, Baiyao Liang, Jun Hu, Dezhou Guo, Minghu Pan, Junfa Zhu, Lifeng Chi
{"title":"Impact of Potassium Doping on a Two-Dimensional Kagome Organic Framework on Ag(111)","authors":"Xingyue Wang, Tianchen Qin, Tian Ma, Sifan You, Jia Wang, Lei Hu, Baiyao Liang, Jun Hu, Dezhou Guo, Minghu Pan, Junfa Zhu, Lifeng Chi","doi":"10.1021/acs.jpclett.4c03344","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03344","url":null,"abstract":"Alkali element doping has significant physical implications for two-dimensional materials, primarily by tuning the electronic structure and carrier concentration. It can enhance interface electronic interactions, providing opportunities for effective charge transfer at metal–organic interfaces. In this work, we investigated the effects of gradually increasing the level of K doping on the lattice structure and electronic properties of an organometallic coordinated Kagome lattice on a Ag(111) surface. With the introduction of K dopants into the 4-fold N–Ag coordinated Kagome lattice, the highly periodic Kagome lattice gradually tends to become discrete. Combining synchrotron radiation photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations, we revealed the mechanism of structural transformation of the lattice, i.e., the change in thermodynamically favored structures caused by competition of electron donors. As an electron donor with a lower ionization energy, K adatoms tend to replace the Ag adatoms and form a more thermodynamically stable N–K coordination structure. Moreover, enhanced charge transfer from K to the Kagome lattice induced a rigid shift of the Fermi level. Our investigation provides new insights for the study of alkali-doped organometallic nanostructures.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"41 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuval Avivi, Juan Julian Santoyo-Flores, Tim Schleif, Sebastian Kozuch
{"title":"Cryogenic Rearrangements of Spiroheptadiyl: Light- or Heavy-Atom Quantum Tunneling?","authors":"Yuval Avivi, Juan Julian Santoyo-Flores, Tim Schleif, Sebastian Kozuch","doi":"10.1021/acs.jpclett.4c02843","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02843","url":null,"abstract":"Triplet 1,4-spiro[2.4]heptadiyl (<b>SHD</b>) has been shown experimentally to undergo rapid ring-opening and subsequent 1,2-hydrogen shift upon generation via photolysis of a diazene precursor at cryogenic temperatures. Modern computational tools elucidate the potential energy surface and kinetics behind this cascade reaction, disproving the earlier hypothesized mechanism invoking hot molecule effects in the first ring-opening step and tunneling in the second hydrogen transfer step. Instead, our results assign the <b>SHD</b> instability to heavy-atom tunneling and a subsequent photochemical hydrogen shift. This essentially is the opposite of the originally proposed mechanism. This case study thus addresses common misconceptions about the fundamental principles of tunneling involving hydrogen or carbon.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"32 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhan Hua Li, Jia Xing He, Jia Yu Li, Ke Xu, Xiao Hu Lv, Ming-de Li, Chao Ping Liu, Kin Man Yu, Jian Dong Ye
{"title":"Native Defect-Dependent Ultrafast Carrier Dynamics in p-Type Dopable Wide-Bandgap NiO","authors":"Zhan Hua Li, Jia Xing He, Jia Yu Li, Ke Xu, Xiao Hu Lv, Ming-de Li, Chao Ping Liu, Kin Man Yu, Jian Dong Ye","doi":"10.1021/acs.jpclett.4c02959","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02959","url":null,"abstract":"NiO is a wide-bandgap p-type metal oxide that has extensive applications in optoelectronics and photocatalysts. Understanding the carrier dynamics in p-type NiO is pivotal for optimizing device performance, yet they remain largely unexplored. In this study, we employed femtosecond transient absorption spectroscopy to delve into the dynamics of photogenerated carriers in NiO films containing distinct prominent native defects: undoped NiO with oxygen vacancies (<i>V</i><sub>O</sub>) and O-rich NiO (denoted as NiO<sub>1+δ</sub>) with nickel vacancies (<i>V</i><sub>Ni</sub>). Our findings unveil significant disparities between the two types of NiO thin films. The undoped NiO film exhibits a broad photoinduced absorption signal spanning the spectral range of 360–600 nm, whereas a photobleaching signal within the spectral range of 400–600 nm is observed in the O-rich NiO<sub>1+δ</sub> film, which can be attributed to their unique native defects. We ascertain that the fast formation of small electron polarons (SEPs) occurs within a delay time of approximately 200 fs. Subsequently, the photogenerated carriers undergo rapid trapping by localized states (e.g., grain boundary states) in undoped NiO and O-rich NiO<sub>1+δ</sub> within time scales of around 1–8 and 5–7 ps, respectively, followed by relatively slow trapping and recombination processes via native defects <i>V</i><sub>O</sub> and <i>V</i><sub>Ni</sub> within time scales of approximately 200 ps and ∼2 ns, respectively. These findings illuminate the fundamental processes governing carrier dynamics in NiO thin films with different native defects, offering crucial insights for the advancement of NiO-based devices.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"24 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Compositionally Tunable Magneto-optical Properties of Lead-Free Halide Perovskite Nanocrystals","authors":"Lin Feng, I-Hsuan Yeh, Pavle V. Radovanovic","doi":"10.1021/acs.jpclett.4c02966","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02966","url":null,"abstract":"Inorganic lead-free metal halide perovskites have garnered much attention as low-toxicity alternatives to lead halide perovskites for luminescence and photovoltaic applications. However, the electronic structure and properties of these materials, including the composition dependence of the band structure, spin–orbit coupling, and Zeeman effects, remain poorly understood. Here, we investigated vacancy-ordered Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9</sub> (X= Cl, Br) perovskite nanocrystals using magnetic circular dichroism spectroscopy. Our results indicate that the excitonic spectra are predominantly composed of direct and indirect band gap transitions and that the Zeeman splitting energy of the direct exciton increases from 0.50 to 0.63 meV at 7 T by substituting Br for Cl. Comparison with analogous results for Cs<sub>2</sub>AgBiCl<sub>6</sub> nanocrystals, obtained by cation substitution, suggests an important effect of charge distribution within electronic bands on the excitonic Zeeman splitting. This work demonstrates that the magneto-optical properties of these materials can be effectively manipulated via chemical composition, suggesting promising applications in photonics, spintronics, and optoelectronics.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"1 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142874356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bin Gao, Xiaowei Mu, Jianming Liu, Jianyong Feng, Huiting Huang, Zhigang Zou, Zhaosheng Li
{"title":"Optimizing Formation Energy Barrier of NiCo-LDH Cocatalyst to Enhance Photoelectrochemical Benzyl Alcohol Oxidation","authors":"Bin Gao, Xiaowei Mu, Jianming Liu, Jianyong Feng, Huiting Huang, Zhigang Zou, Zhaosheng Li","doi":"10.1021/acs.jpclett.4c03065","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03065","url":null,"abstract":"Using organic oxidation reactions to replace the oxygen evolution reaction is a promising approach for producing high-value organic products and hydrogen. Here, we report a photoelectrochemical benzyl alcohol oxidation system based on an α-Fe<sub>2</sub>O<sub>3</sub> photoanode coated with a NiCo-layered double hydroxide (NiCo-LDH) cocatalyst. By adjustment of the relative content of Ni and Co in the NiCo-LDH, the optimized photoanode achieved a benzyl alcohol conversion efficiency of 99.1% and benzoic acid selectivity of 90.9%. Experimental studies revealed that the benzyl alcohol oxidation reaction proceeds via an indirect catalytic mechanism involving high-valence species of the NiCo-LDH cocatalyst. Co in NiCo-LDH reduced the formation energy barrier and oxidative capability of the high-valence species, thereby influencing the performance of the photoanode. This work provides insights into the crucial role of cocatalyst composition in organic reaction oxidation and contributes to developing various photoelectrochemical organic oxidation systems.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"88 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Shakiba, Adam B. Philips, Jochen Autschbach, Alexey V. Akimov
{"title":"Machine Learning Mapping Approach for Computing Spin Relaxation Dynamics","authors":"Mohammad Shakiba, Adam B. Philips, Jochen Autschbach, Alexey V. Akimov","doi":"10.1021/acs.jpclett.4c03293","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03293","url":null,"abstract":"In this work, a machine learning mapping approach for predicting the properties of atomistic systems is reported. Within this approach, the atomic orbital overlap, density, or Kohn-Sham (KS) Fock matrix elements obtained at a low level of theory such as extended tight-binding have been used as input features to predict the electric field gradient (EFG) tensors at a higher level of theory such as those obtained with hybrid functionals. It is shown that the machine-learning-predicted EFG tensors can be used to compute spin relaxation rates of several ions in aqueous solutions. From only a fraction of data used in direct calculation, one can predict the quadrupolar isotropic spin relaxation rates with good accuracy, achieving relative errors between about 2–8% for different ions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"268 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}