Carbazole derivatives have long been known to exhibit excellent photoconductivity. Molecular arrangement control using intermolecular hydrogen bonds is an effective method for controlling carrier transport properties. In this work, we synthesized N,N′-ditetradecyl-9-methyl-3,6-carbazoledicarboxamide (C14CBC) by introducing two tetradecylamide (−CONHC14H29) chains into the 3,6-position of 9-methyl-carbazole and considered electronic structure, phase transition behavior, molecular assembly structure, dielectric property, and photoconductivity of C14CBC. C14CBC forms a 1D π-stacking column structure by intermolecular amide hydrogen bonding. C14CBC shows a solid–solid phase transition at 346 K and a melting point at 458 K. The temperature- and frequency-dependent dielectric constants show a response due to the dynamics of polar amide units above 400 K. The conductivity of the S1 and S2 phases is governed by the trap level and the HOMO–LUMO band gap. In the dynamic high temperature solid phase, the activation energy decreased upon photoirradiation.
{"title":"Dynamic Polar Hydrogen Bonds and Photoconductivity of an Alkylamide-Substituted Carbazole Derivative","authors":"Ryohei Mizoue, Takashi Takeda, Shun Dekura, Tomoyuki Akutagawa","doi":"10.1021/acs.jpcc.4c06143","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06143","url":null,"abstract":"Carbazole derivatives have long been known to exhibit excellent photoconductivity. Molecular arrangement control using intermolecular hydrogen bonds is an effective method for controlling carrier transport properties. In this work, we synthesized <i>N</i>,<i>N</i>′-ditetradecyl-9-methyl-3,6-carbazoledicarboxamide (<b>C14CBC</b>) by introducing two tetradecylamide (−CONHC<sub>14</sub>H<sub>29</sub>) chains into the 3,6-position of 9-methyl-carbazole and considered electronic structure, phase transition behavior, molecular assembly structure, dielectric property, and photoconductivity of <b>C14CBC</b>. <b>C14CBC</b> forms a 1D π-stacking column structure by intermolecular amide hydrogen bonding. <b>C14CBC</b> shows a solid–solid phase transition at 346 K and a melting point at 458 K. The temperature- and frequency-dependent dielectric constants show a response due to the dynamics of polar amide units above 400 K. The conductivity of the S1 and S2 phases is governed by the trap level and the HOMO–LUMO band gap. In the dynamic high temperature solid phase, the activation energy decreased upon photoirradiation.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"70 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1021/acs.jpcc.4c03966
Archith Rayabharam, Narayana R. Aluru
Proton tunneling through 2D materials such as graphene and hexagonal boron nitride (hBN) was demonstrated experimentally in 2014 and has garnered significant attention in the field of nanotechnology due to its potential applications in energy storage, fuel cells, catalysis, and hydrogen isotope separation. Furthermore, engineering defects on similar 2D materials have also contributed to advancing the realization of these applications. Here, we investigate proton tunneling through hBN to improve our understanding of how engineering defects in hBN can be used to modulate proton permeation. Specifically, we employ a 1D transition state model to simulate the permeation of protons through both pristine and defective hBN. This model utilizes the energy barriers of protons permeating across hBN to estimate transmission coefficients, tunneling probabilities, and fluxes. To enhance the accuracy of our flux estimates, we take into account the zero-point energies of protons in water and discuss a method to increase the proton flux through hBN by exciting protons vibrationally. After the incorporation of zero-point energies, our flux calculations indicate that the isotopes of hydrogen ions can be separated at low temperatures using engineered defects in hBN. The results of this study provide insights into engineering defects on hBN, which can lead to the development of membranes with high proton conductivity while remaining impermeable to other species. These findings have significant implications for the design and optimization of advanced materials for various nanoscale applications.
{"title":"Modulation of Proton Permeation through Defect Engineering in Hexagonal Boron Nitride","authors":"Archith Rayabharam, Narayana R. Aluru","doi":"10.1021/acs.jpcc.4c03966","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c03966","url":null,"abstract":"Proton tunneling through 2D materials such as graphene and hexagonal boron nitride (hBN) was demonstrated experimentally in 2014 and has garnered significant attention in the field of nanotechnology due to its potential applications in energy storage, fuel cells, catalysis, and hydrogen isotope separation. Furthermore, engineering defects on similar 2D materials have also contributed to advancing the realization of these applications. Here, we investigate proton tunneling through hBN to improve our understanding of how engineering defects in hBN can be used to modulate proton permeation. Specifically, we employ a 1D transition state model to simulate the permeation of protons through both pristine and defective hBN. This model utilizes the energy barriers of protons permeating across hBN to estimate transmission coefficients, tunneling probabilities, and fluxes. To enhance the accuracy of our flux estimates, we take into account the zero-point energies of protons in water and discuss a method to increase the proton flux through hBN by exciting protons vibrationally. After the incorporation of zero-point energies, our flux calculations indicate that the isotopes of hydrogen ions can be separated at low temperatures using engineered defects in hBN. The results of this study provide insights into engineering defects on hBN, which can lead to the development of membranes with high proton conductivity while remaining impermeable to other species. These findings have significant implications for the design and optimization of advanced materials for various nanoscale applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"17 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1021/acs.jpcc.4c04844
Md Tohidul Islam, Kacey Pearce, Baishakhi Mazumder, Scott Broderick
NbN has become an important material for superconducting applications, largely due to its ability to have a high superconducting transition temperature (TC) compared with other transition metal nitrides. However, there is still a need to enhance the TC further as well as to develop a framework for rapidly scanning the material design space and fine-tuning the processing parameters for optimized properties. The unique integrated approach developed and applied here enhances NbN TC through an ensemble modeling approach to develop general design rules coupling categorical and quantitative data with an optimization approach for fine-tuning the film thickness, substrate chemistry, and processing parameters. As experimental data are used to build the models, the effects of defects are inherently captured. Through this unique framework, a combination of controllable factors are identified which lead to a calculated increase of 16.4% in the TC of the NbN film as compared with the best NbN film using the same deposition methods.
{"title":"Data-Driven Transition Temperature Enhancement of NbN Layered Structures: A Framework for Quantum Materials Design","authors":"Md Tohidul Islam, Kacey Pearce, Baishakhi Mazumder, Scott Broderick","doi":"10.1021/acs.jpcc.4c04844","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04844","url":null,"abstract":"NbN has become an important material for superconducting applications, largely due to its ability to have a high superconducting transition temperature (<i>T</i><sub>C</sub>) compared with other transition metal nitrides. However, there is still a need to enhance the <i>T</i><sub>C</sub> further as well as to develop a framework for rapidly scanning the material design space and fine-tuning the processing parameters for optimized properties. The unique integrated approach developed and applied here enhances NbN <i>T</i><sub>C</sub> through an ensemble modeling approach to develop general design rules coupling categorical and quantitative data with an optimization approach for fine-tuning the film thickness, substrate chemistry, and processing parameters. As experimental data are used to build the models, the effects of defects are inherently captured. Through this unique framework, a combination of controllable factors are identified which lead to a calculated increase of 16.4% in the <i>T</i><sub>C</sub> of the NbN film as compared with the best NbN film using the same deposition methods.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"70 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c06141
Jie Fu, Shuhua Chen, Lin Yuan, Qi Pan, Zeke Liu, Jinxing Chen, Panpan Xu, Qiao Zhang, Muhan Cao
Lead halide perovskite nanocrystals (NCs) have undergone great development in the optoelectrical field. The mixed cation perovskite Cs1–xFAxPbI3 NCs exhibit great potential in photoelectric devices because of their improved structural stability and increased light absorption range. However, achieving homogeneous Cs1–xFAxPbI3 NCs with fewer surface defects remains challenging. In this work, we employ a two-step exchange-passivation method for the preparation of Cs1–xFAxPbI3 NCs and adopt a surface repair strategy based on pseudohalide ions to decrease the surface trap density. Owing to the similar radius of the pseudohalide ions to that of the iodine ions and their strong electronegativity from F atoms, the pseudohalide ions can fill the surface iodine vacancies of the NCs and form Hydron bonds with FA+, resulting in improved photoelectric properties and suppressed nonrecombination of carriers. This work highlights the importance of surface chemistry in perovskite NCs and may provide insights for synthesizing high-performance mixed A-site perovskite NCs for future applications.
{"title":"Pseudohalide Anion Surface Engineering for Mixed Cation Perovskite Nanocrystals","authors":"Jie Fu, Shuhua Chen, Lin Yuan, Qi Pan, Zeke Liu, Jinxing Chen, Panpan Xu, Qiao Zhang, Muhan Cao","doi":"10.1021/acs.jpcc.4c06141","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06141","url":null,"abstract":"Lead halide perovskite nanocrystals (NCs) have undergone great development in the optoelectrical field. The mixed cation perovskite Cs<sub>1–<i>x</i></sub>FA<i><sub>x</sub></i>PbI<sub>3</sub> NCs exhibit great potential in photoelectric devices because of their improved structural stability and increased light absorption range. However, achieving homogeneous Cs<sub>1–<i>x</i></sub>FA<i><sub>x</sub></i>PbI<sub>3</sub> NCs with fewer surface defects remains challenging. In this work, we employ a two-step exchange-passivation method for the preparation of Cs<sub>1–<i>x</i></sub>FA<i><sub>x</sub></i>PbI<sub>3</sub> NCs and adopt a surface repair strategy based on pseudohalide ions to decrease the surface trap density. Owing to the similar radius of the pseudohalide ions to that of the iodine ions and their strong electronegativity from F atoms, the pseudohalide ions can fill the surface iodine vacancies of the NCs and form Hydron bonds with FA<sup>+</sup>, resulting in improved photoelectric properties and suppressed nonrecombination of carriers. This work highlights the importance of surface chemistry in perovskite NCs and may provide insights for synthesizing high-performance mixed A-site perovskite NCs for future applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"35 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c04978
Ephraiem S. Sarabamoun, Pramod Aryal, Jonathan M. Bietsch, Maurice Curran, Sugandha Verma, Grayson Johnson, Lucy U. Yoon, Amelia G. Reid, Esther H. R. Tsai, Charles W. Machan, Christopher Paolucci, Guijun Wang, Joshua J. Choi
We contrast the switching of photoluminescence (PL) of PbS quantum dots (QDs) cross-linked with photochromic diarylethene molecules with different end groups, 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (1C) and 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenethiocarboxylic acid] (2T). Our results show that the QDs cross-linked with the carboxylic acid end group molecules (1C) exhibit a greater amount of switching in photoluminescence intensity compared to QDs cross-linked with the thiocarboxylic acid end group (2T). We also demonstrate that regardless of the molecule used, greater switching amounts are observed for smaller quantum dots. Varying these parameters allows for the fabrication of photoswitches with tunable PL change. We relate these observations to the differences in the HOMO energy levels between the QDs and the photochromic molecules. Our findings demonstrate how the size of the QDs and the energy levels of the linker ligands influences the charge tunneling rate and thus the PL switching performance in tunneling-based photoswitches.
我们对比了与具有不同端基的光致变色二元蒽分子（4、4′-（1-环戊烯-1,2-二基）双[5-甲基-2-噻吩羧酸]（1C）和 4,4′-（1-环戊烯-1,2-二基）双[5-甲基-2-噻吩硫代羧酸]（2T）。我们的研究结果表明，与硫代羧酸端基交联的 QDs（2T）相比，与羧酸端基分子交联的 QDs（1C）表现出更大的光致发光强度变化。我们还证明，无论使用哪种分子，较小的量子点都能观察到更大的切换量。改变这些参数可以制造出具有可调 PL 变化的光开关。我们将这些观察结果与量子点和光致变色分子之间的 HOMO 能级差异联系起来。我们的研究结果表明了 QDs 的尺寸和链接配体的能级如何影响电荷隧道率，从而影响基于隧道的光开关的光致变色性能。
{"title":"Photoluminescence Switching in Quantum Dots Connected with Carboxylic Acid and Thiocarboxylic Acid End-Group Diarylethene Molecules","authors":"Ephraiem S. Sarabamoun, Pramod Aryal, Jonathan M. Bietsch, Maurice Curran, Sugandha Verma, Grayson Johnson, Lucy U. Yoon, Amelia G. Reid, Esther H. R. Tsai, Charles W. Machan, Christopher Paolucci, Guijun Wang, Joshua J. Choi","doi":"10.1021/acs.jpcc.4c04978","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04978","url":null,"abstract":"We contrast the switching of photoluminescence (PL) of PbS quantum dots (QDs) cross-linked with photochromic diarylethene molecules with different end groups, 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (<b>1C</b>) and 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenethiocarboxylic acid] (<b>2T</b>). Our results show that the QDs cross-linked with the carboxylic acid end group molecules (<b>1C</b>) exhibit a greater amount of switching in photoluminescence intensity compared to QDs cross-linked with the thiocarboxylic acid end group (<b>2T</b>). We also demonstrate that regardless of the molecule used, greater switching amounts are observed for smaller quantum dots. Varying these parameters allows for the fabrication of photoswitches with tunable PL change. We relate these observations to the differences in the HOMO energy levels between the QDs and the photochromic molecules. Our findings demonstrate how the size of the QDs and the energy levels of the linker ligands influences the charge tunneling rate and thus the PL switching performance in tunneling-based photoswitches.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"74 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c06690
Yaxin Chen, Harold H. Kung
It has been of great interest to understand the relationships between the potential of a metal catalyst and its thermochemical catalytic activity, especially in an aqueous phase environment. In the literature, there are correlations of open circuit potential with reaction rates or surface concentrations of the reaction intermediates. In this study, we measured the open circuit potential (OCP) of a Au gauze during selective oxidation of glycerol to glyceric acid and hydrogen peroxide in a basic solution as a function of hydroxide and alcoholate concentrations. It is found that applying a potential to the Au catalyst has no influence on the reaction rate. Although a rough correlation appears to exist between the OCP and reaction rate, the data are better fit to an equation which assumes that the potential of the metal (i.e., the OCP) is in equilibrium with the electrochemical potential of the solution, which is defined by the thermodynamic activities of the oxidizing and reducing species. The equation: OCP = constant + Σox[(RT/FZox) ln[Ox]] – Σred[(RT/FZred) ln[Red]] implicitly assumes that the Au metal functions as a probing electrode. It is further found that this equation also applies to the Au-catalyzed H2O2 oxidation/decomposition reaction in a basic medium and possibly to formic acid dehydrogenation. We postulate that the apparent correlation between OCP and reaction rate is due to the fact that the reaction rate is proportional to the concentrations of the reaction products and/or reactants that define the electrochemical potential of the solution.
{"title":"Open Circuit Potential of a Au Catalyst during Selective Oxidation of Glycerol","authors":"Yaxin Chen, Harold H. Kung","doi":"10.1021/acs.jpcc.4c06690","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06690","url":null,"abstract":"It has been of great interest to understand the relationships between the potential of a metal catalyst and its thermochemical catalytic activity, especially in an aqueous phase environment. In the literature, there are correlations of open circuit potential with reaction rates or surface concentrations of the reaction intermediates. In this study, we measured the open circuit potential (OCP) of a Au gauze during selective oxidation of glycerol to glyceric acid and hydrogen peroxide in a basic solution as a function of hydroxide and alcoholate concentrations. It is found that applying a potential to the Au catalyst has no influence on the reaction rate. Although a rough correlation appears to exist between the OCP and reaction rate, the data are better fit to an equation which assumes that the potential of the metal (i.e., the OCP) is in equilibrium with the electrochemical potential of the solution, which is defined by the thermodynamic activities of the oxidizing and reducing species. The equation: OCP = constant + Σ<sub>ox</sub>[(<i>RT</i>/<i>FZ</i><sub>ox</sub>) ln[Ox]] – Σ<sub>red</sub>[(<i>RT</i>/<i>FZ</i><sub>red</sub>) ln[Red]] implicitly assumes that the Au metal functions as a probing electrode. It is further found that this equation also applies to the Au-catalyzed H<sub>2</sub>O<sub>2</sub> oxidation/decomposition reaction in a basic medium and possibly to formic acid dehydrogenation. We postulate that the apparent correlation between OCP and reaction rate is due to the fact that the reaction rate is proportional to the concentrations of the reaction products and/or reactants that define the electrochemical potential of the solution.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"74 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c06027
Raheel Hammad, Snehith Adabala, Soumya Ghosh
Heterostructures are ubiquitous in many optoelectronic devices and as photocatalysts. One of the key features of a heterojunction is proper band alignment between the two materials. Estimation of the correct relative band positions with density functional theory (DFT)-based electronic structure calculations is often constrained by the accuracy and cost associated with the various DFT functionals. In this study, we introduce a novel computational approach that achieves band alignments closely matching experimental results with the widely used PBE functional. We specifically examine the well-documented MoO3/MoS2 system, a type-II heterojunction. In our setup, the MoS2 layers are kept as they are, but for MoO3, the individual layers are chosen differently. These alternative layers have higher surface energy, and hence, the band edges are higher than those of the conventional layers. This shift in band edges of the alternative MoO3 layers changes the band alignment in the MoO3/MoS2 heterojunction from type-III to the experimentally observed type-II character. We also extend this computational strategy to additional systems, demonstrating its versatility and effectiveness.
在许多光电设备和光催化剂中，异质结构无处不在。异质结的关键特征之一是两种材料之间的适当带排列。利用基于密度泛函理论（DFT）的电子结构计算来估计正确的相对能带位置，往往会受到各种 DFT 函数的精度和成本的限制。在本研究中，我们介绍了一种新颖的计算方法，它能利用广泛使用的 PBE 函数实现与实验结果接近的能带排列。我们特别研究了记录详实的 MoO3/MoS2 系统，这是一种 II 型异质结。在我们的设置中，MoS2 层保持原样，但对于 MoO3，单个层的选择有所不同。这些替代层具有更高的表面能，因此其带边高于传统层。替代 MoO3 层带边的这种偏移改变了 MoO3/MoS2 异质结的带排列，从 III 型变为实验观察到的 II 型。我们还将这一计算策略扩展到其他系统，证明了它的多功能性和有效性。
{"title":"Choice of Layering and Band Alignment in 2D Heterostructures","authors":"Raheel Hammad, Snehith Adabala, Soumya Ghosh","doi":"10.1021/acs.jpcc.4c06027","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06027","url":null,"abstract":"Heterostructures are ubiquitous in many optoelectronic devices and as photocatalysts. One of the key features of a heterojunction is proper band alignment between the two materials. Estimation of the correct relative band positions with density functional theory (DFT)-based electronic structure calculations is often constrained by the accuracy and cost associated with the various DFT functionals. In this study, we introduce a novel computational approach that achieves band alignments closely matching experimental results with the widely used PBE functional. We specifically examine the well-documented MoO<sub>3</sub>/MoS<sub>2</sub> system, a type-II heterojunction. In our setup, the MoS<sub>2</sub> layers are kept as they are, but for MoO<sub>3</sub>, the individual layers are chosen differently. These alternative layers have higher surface energy, and hence, the band edges are higher than those of the conventional layers. This shift in band edges of the alternative MoO<sub>3</sub> layers changes the band alignment in the MoO<sub>3</sub>/MoS<sub>2</sub> heterojunction from type-III to the experimentally observed type-II character. We also extend this computational strategy to additional systems, demonstrating its versatility and effectiveness.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"7 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c06756
Yanhan Ren, Shi Qiu, Shiji Li, Anbing Zhang, Hongsheng Liu, Sergei Guretskii, Dmitry Karpinsky, Rui Li, Junfeng Gao
Due to the remarkably strong second-harmonic generation (SHG), two-dimensional materials have excellent potential applications in nonlinear optics (NLOs). However, their SHG efficiency remains limited due to the short light–matter interaction length. Through van der Waals heterostructure (vdWHS) engineering, it is possible to elongate light–matter interacting length and control structural symmetries and anisotropies. Here, vdWHSs were built by noncentrosymmetric monolayer g-C3N4 and centrosymmetric BiVO4 slabs with varying layers. Their structural stabilities, electronic band structures, band alignments, and SHG susceptibilities have been systematically simulated by DFT calculations. Interestingly, BiVO4 slabs with two or more layers form stable type-II heterostructures with g-C3N4, exhibiting the interlayer separation of photogenerated carriers. Besides, vdWHSs broke the centrosymmetry of BiVO4, resulting in remarkable and complex SHG responses. The in-plane SHG susceptibility of g-C3N4/BiVO4 vdWHSs exceeds 100 pm/V in the 700–800 nm range and gradually decreases as the thickness increases. Significant polarized out-of-plane SHG was introduced by vdWHS. The χzxx(2), χzxy(2), and χzyy(2) components show multiple high peaks at 400–780 and 780–1240 nm, with intensities 3 times larger than that of LiNbO3. These indicate that such vdWHS composites hold considerable potential for NLO in both visible and infrared light regions, which are important for advanced optical communication and photonic computing systems.
{"title":"Enhanced Anisotropic Second Harmonic Generation in Type-II van der Waals Heterostructures of g-C3N4/BiVO4","authors":"Yanhan Ren, Shi Qiu, Shiji Li, Anbing Zhang, Hongsheng Liu, Sergei Guretskii, Dmitry Karpinsky, Rui Li, Junfeng Gao","doi":"10.1021/acs.jpcc.4c06756","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06756","url":null,"abstract":"Due to the remarkably strong second-harmonic generation (SHG), two-dimensional materials have excellent potential applications in nonlinear optics (NLOs). However, their SHG efficiency remains limited due to the short light–matter interaction length. Through van der Waals heterostructure (vdWHS) engineering, it is possible to elongate light–matter interacting length and control structural symmetries and anisotropies. Here, vdWHSs were built by noncentrosymmetric monolayer g-C<sub>3</sub>N<sub>4</sub> and centrosymmetric BiVO<sub>4</sub> slabs with varying layers. Their structural stabilities, electronic band structures, band alignments, and SHG susceptibilities have been systematically simulated by DFT calculations. Interestingly, BiVO<sub>4</sub> slabs with two or more layers form stable type-II heterostructures with g-C<sub>3</sub>N<sub>4</sub>, exhibiting the interlayer separation of photogenerated carriers. Besides, vdWHSs broke the centrosymmetry of BiVO<sub>4</sub>, resulting in remarkable and complex SHG responses. The in-plane SHG susceptibility of g-C<sub>3</sub>N<sub>4</sub>/BiVO<sub>4</sub> vdWHSs exceeds 100 pm/V in the 700–800 nm range and gradually decreases as the thickness increases. Significant polarized out-of-plane SHG was introduced by vdWHS. The χ<sub>zxx</sub><sup>(2)</sup>, χ<sub>zxy</sub><sup>(2)</sup>, and χ<sub>zyy</sub><sup>(2)</sup> components show multiple high peaks at 400–780 and 780–1240 nm, with intensities 3 times larger than that of LiNbO<sub>3</sub>. These indicate that such vdWHS composites hold considerable potential for NLO in both visible and infrared light regions, which are important for advanced optical communication and photonic computing systems.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"18 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c04015
Guoqing Liu, Jiajun Mo, Zeyi Lu, Qinghang Zhang, Puyue Xia, Min Liu
This study systematically investigates the spin glass behavior of the double perovskite Ca2FeReO6. Building on previous research, we developed a formula to quantify the distribution of ions at the B-site, incorporating next-nearest-neighbor interactions. Using molecular field theory and Monte Carlo simulations, we examined the influence of different arrangements of B-site ions on frustration effects. The B-site is divided into a-site and b-site, with the number of nearest neighbors from Fea to Feb (and vice versa) defined as Zx (Zy). The strongest frustration occurs when Zx (or Zy) ≈ 2 and Zy (or Zx) ≈ 5, resulting in a radial pattern under comparable conditions. Significant frustration effects are also observed when Zx (or Zy) ≈ 3 and Zy (or Zx) ≈ 4. These effects are reflected in the variations in ground-state magnetization and the thermal energy step in relation to Zx and Zy. The model proposed in this study is applicable to most B-site disordered perovskite systems as well as other chemically disordered frustrated systems.
本研究系统地探讨了双包晶 Ca2FeReO6 的自旋玻璃行为。在以往研究的基础上，我们开发了一种公式来量化 B 位离子的分布，并将近邻相互作用纳入其中。利用分子场理论和蒙特卡罗模拟，我们研究了 B 位离子的不同排列对挫折效应的影响。B 位分为 a 位和 b 位，从 Fea 到 Feb（反之亦然）的最近邻数定义为 Zx (Zy)。当 Zx（或 Zy）≈2 和 Zy（或 Zx）≈5 时，会产生最强的挫折感，从而在类似条件下形成放射状图案。当 Zx（或 Zy）≈3 和 Zy（或 Zx）≈4 时，也会出现明显的挫折效应。这些效应反映在与 Zx 和 Zy 有关的基态磁化和热能阶跃的变化中。本研究提出的模型适用于大多数 B 位无序包晶体系以及其他化学无序受挫体系。
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Pub Date : 2024-11-21DOI: 10.1021/acs.jpcc.4c07057
Dong H. Zhang, Xingan Wang, Mingfei Zhou, Feng Gai
Published as part of <i>The Journal of Physical Chemistry C</i> special issue “Xueming Yang Festschrift”. <named-content content-type="bio-pic" type="simple"><img alt="" src="/cms/10.1021/acs.jpcc.4c07057/asset/images/medium/jp4c07057_0001.gif"/></named-content> It is our pleasure to preface this Festschrift to celebrate the remarkable scientific career of Professor Xueming Yang. Xueming is an innovative and pioneering experimental physical chemist. Throughout his academic career, he has made significant contributions to a wide range of technological advancements and scientific discoveries, spanning from advancing the fundamental understanding of reaction dynamics in the gas phase and at surfaces to promoting the development of free-electron lasers (FEL) in China. Xueming was born in 1962 and grew up in Zhejiang province, China. He developed a strong passion for chemistry during his middle school years. He was among the first cohort of university students after the college entrance examination was reinstated in China and received a bachelor degree at Zhejiang Normal University in 1982. After three years of study on high-resolution spectroscopy of polyatomic molecules as a master student, under the guidance of Professor Qingshi Zhu and Professor Cunhao Zhang at Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, he enrolled in the Ph.D. program at the University of California, Santa Barbara, where he met his supervisor, Professor Alec Wodtke. During his Ph.D. study, he utilized the stimulated emission pumping (SEP) technique to investigate the spectroscopy and collisional dynamics of molecules with highly excited vibrational states. He then performed postdoctoral research with Professor Giacinto Scoles at Princeton University and Professor Yuan T. Lee at Lawrence Berkeley National Laboratory. During his two and a half years at Berkeley, Xueming managed to build a sophisticated crossed molecular beams instrument, an experience that became a valuable asset in his research endeavor. Since then, Xueming has developed various high-resolution molecular beam apparatuses and novel experimental methods that have played an important role in the study and understanding of reaction dynamics and mechanisms at the microscopic level. He believes that the training at Berkeley was pivotal in helping him discover his strong and genuine desire in developing scientific instruments and conducting state-of-the-art experimental research in chemical dynamics. In 1995, Xueming started his independent research career at the Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica in Taipei. During that period, he successfully developed three crossed molecular beams apparatuses: a universal molecular beam instrument employing electron impact ionization detection, a crossed beam apparatus using vacuum ultraviolet (VUV) synchrotron radiation, and a high-resolution crossed beam H atom Rydberg tagging machine. By using the H atom Rydberg tagging
由于在美国劳伦斯伯克利国家实验室先进光源设施的工作经历，徐学明一直对研制具有迄今为止不可能实现的科学研究所需的特性和亮度的极紫外激光光源感兴趣。自2010年代初以来，学明与中国科学院上海应用物理研究所的同事合作，在极紫外激光光源的研制方面取得了重大进展，并在他的努力下，在中国建立了世界上第一个大规模极紫外激光光源用户设施。未来几年，学明将重点建设深圳超导软X射线自由电子激光器（S3FEL）。该设施将在软 X 射线范围内产生明亮的激光，使其成为物理和化学科学研究的更强大工具。学明在科学领域的杰出贡献得到了包括未来物理科学奖和洪堡研究奖在内的众多著名奖项的认可。他当选为中国科学院院士，并被任命为哥廷根大学高斯教授。此外，他还当选为美国物理学会和英国皇家化学会的研究员。学明是反应动力学领域的领军人物，其重大贡献远远超出了他的开创性研究。他为年轻科学家营造了一个理想的科研环境，帮助他们解决反应动力学领域复杂而迷人的问题。对于许多年轻研究人员来说，他是一位备受尊敬的导师和支持性顾问。作为他的同事和朋友，我们深深感谢他广阔的视野、强有力的领导、无限的热情、真诚的合作和珍贵的友谊。这本论文集汇集了学明的学生、博士后、合作者和朋友们的贡献。我们很荣幸能庆祝他取得的卓越成就，并期待他在未来取得更多成就。本序言所表达的观点仅代表作者本人，不代表美国化学学会的观点。本序言联合发表于《物理化学学报》（The Journal of Physical Chemistry A）和《物理化学学报》（The Journal of Physical Chemistry C）。
{"title":"Tribute to Xueming Yang","authors":"Dong H. Zhang, Xingan Wang, Mingfei Zhou, Feng Gai","doi":"10.1021/acs.jpcc.4c07057","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07057","url":null,"abstract":"Published as part of <i>The Journal of Physical Chemistry C</i> special issue “Xueming Yang Festschrift”. <named-content content-type=\"bio-pic\" type=\"simple\"><img alt=\"\" src=\"/cms/10.1021/acs.jpcc.4c07057/asset/images/medium/jp4c07057_0001.gif\"/></named-content> It is our pleasure to preface this Festschrift to celebrate the remarkable scientific career of Professor Xueming Yang. Xueming is an innovative and pioneering experimental physical chemist. Throughout his academic career, he has made significant contributions to a wide range of technological advancements and scientific discoveries, spanning from advancing the fundamental understanding of reaction dynamics in the gas phase and at surfaces to promoting the development of free-electron lasers (FEL) in China. Xueming was born in 1962 and grew up in Zhejiang province, China. He developed a strong passion for chemistry during his middle school years. He was among the first cohort of university students after the college entrance examination was reinstated in China and received a bachelor degree at Zhejiang Normal University in 1982. After three years of study on high-resolution spectroscopy of polyatomic molecules as a master student, under the guidance of Professor Qingshi Zhu and Professor Cunhao Zhang at Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, he enrolled in the Ph.D. program at the University of California, Santa Barbara, where he met his supervisor, Professor Alec Wodtke. During his Ph.D. study, he utilized the stimulated emission pumping (SEP) technique to investigate the spectroscopy and collisional dynamics of molecules with highly excited vibrational states. He then performed postdoctoral research with Professor Giacinto Scoles at Princeton University and Professor Yuan T. Lee at Lawrence Berkeley National Laboratory. During his two and a half years at Berkeley, Xueming managed to build a sophisticated crossed molecular beams instrument, an experience that became a valuable asset in his research endeavor. Since then, Xueming has developed various high-resolution molecular beam apparatuses and novel experimental methods that have played an important role in the study and understanding of reaction dynamics and mechanisms at the microscopic level. He believes that the training at Berkeley was pivotal in helping him discover his strong and genuine desire in developing scientific instruments and conducting state-of-the-art experimental research in chemical dynamics. In 1995, Xueming started his independent research career at the Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica in Taipei. During that period, he successfully developed three crossed molecular beams apparatuses: a universal molecular beam instrument employing electron impact ionization detection, a crossed beam apparatus using vacuum ultraviolet (VUV) synchrotron radiation, and a high-resolution crossed beam H atom Rydberg tagging machine. By using the H atom Rydberg tagging ","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"63 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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