Pyrene-based molecules often suffer from the “aggregation-caused quenching” (ACQ) effect because of their rigid planar structure having several π–π stacking interactions, which limit their applications as solid-state luminescent materials. From this perspective, it has been strategized to develop two compounds: 2-(pyren-1-yl)-4,6-bis(4-vinylphenyl)-1,3,5-triazine (VinTr) and 4-chloro-N,N-diphenyl-6-(pyren-1-yl)-1,3,5-triazin-2-amine (PyTrDA) in such a way that pyrene triazine frameworks are transformed into “aggregation-induced enhanced emission” (AIEE)-active molecules. All of the compounds showed positive responses to the quenching of trinitrotoluene (TNT). Within these compounds, PyTrDA showed excellent results on sensing TNT with a high level of sensitivity (limit of detection = 216 pM in solution and ∼7.0 ppb in the vapor phase) and selectivity, extending the results from the solution to the vapor phase. The quenching process is due to the photoinduced electron transfer (PET) from the probe (PyTrDA) to the analyte (TNT), which was confirmed by transient absorption spectroscopy. In addition to the relatively large quantum yield of PyTrDA, the morphology transformation from a planar sheet-type structure (observed in PyTr) to a vertically grown nanorod (in PyTrDA) offers increased surface area. The vertically grown nanostructural morphology of PyTrDA should properly facilitate the diffusion of TNT molecules and provide a confined environment, where one-to-one host–guest interactions between the probe molecule and analytes are possible. To the best of our knowledge, this is the first study that explores the role of nanostructural morphology with an enhanced surface area for improved TNT sensing using small organic molecules.
{"title":"Pyrene-Based AIEE-Active Vertically Grown Luminescent Material for Selective and Sensitive Detection of TNT Vapor","authors":"Ram Prasad Bhatta, Ajeet Singh, Priya Bhandari, Tirupati Chander Sharma, Pramod Soni, Anindya Datta, Inamur Rahaman Laskar","doi":"10.1021/acs.jpcc.4c04823","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04823","url":null,"abstract":"Pyrene-based molecules often suffer from the “aggregation-caused quenching” (ACQ) effect because of their rigid planar structure having several π–π stacking interactions, which limit their applications as solid-state luminescent materials. From this perspective, it has been strategized to develop two compounds: 2-(pyren-1-yl)-4,6-bis(4-vinylphenyl)-1,3,5-triazine (VinTr) and 4-chloro-<i>N</i>,<i>N</i>-diphenyl-6-(pyren-1-yl)-1,3,5-triazin-2-amine (PyTrDA) in such a way that pyrene triazine frameworks are transformed into “aggregation-induced enhanced emission” (AIEE)-active molecules. All of the compounds showed positive responses to the quenching of trinitrotoluene (TNT). Within these compounds, PyTrDA showed excellent results on sensing TNT with a high level of sensitivity (limit of detection = 216 pM in solution and ∼7.0 ppb in the vapor phase) and selectivity, extending the results from the solution to the vapor phase. The quenching process is due to the photoinduced electron transfer (PET) from the probe (PyTrDA) to the analyte (TNT), which was confirmed by transient absorption spectroscopy. In addition to the relatively large quantum yield of PyTrDA, the morphology transformation from a planar sheet-type structure (observed in PyTr) to a vertically grown nanorod (in PyTrDA) offers increased surface area. The vertically grown nanostructural morphology of PyTrDA should properly facilitate the diffusion of TNT molecules and provide a confined environment, where one-to-one host–guest interactions between the probe molecule and analytes are possible. To the best of our knowledge, this is the first study that explores the role of nanostructural morphology with an enhanced surface area for improved TNT sensing using small organic molecules.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142487122","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05999
Franky Bernal, Erika J. Riffe, Shane W. Devlin, Sebastien Hamel, Rebecca K. Lindsey, Alexander H. Reid, Mianzhen Mo, Duan Luo, Patrick Kramer, Xiaozhe Shen, Athavan Nadarajah, Alastair Stacey, Steven Prawer, Heather D. Whitley, Craig P. Schwartz, Richard J. Saykally
Structural details of the proposed solid–liquid phase transition of carbon have remained elusive, despite years of study. While it is theorized that novel carbon materials form from a liquid precursor, experimental studies have lacked the temporal and spatial resolution necessary to fully characterize the purported liquid state. Here we utilize megaelectronvolt-ultrafast electron diffraction (MeV-UED) to study laser irradiated submicron diamond thin films in a pump–probe scheme with picosecond time resolution to visualize potential structural changes of excited diamond. We probe the structure of diamond using a combination of fluences (13, 40 J/cm2) and time delays (10, 25, 100 ps), but observe negligible changes in the static diffraction pattern of diamond and an overall decrease in diffraction intensity up to 100 ps after the excitation pulse. We thus conclude that no appreciable amount of liquid or graphitized carbon is present and highlight the structural resilience of bulk diamond to intense 800 nm ultrafast laser pulses.
{"title":"Response of fs-Laser-Irradiated Diamond by Ultrafast Electron Diffraction","authors":"Franky Bernal, Erika J. Riffe, Shane W. Devlin, Sebastien Hamel, Rebecca K. Lindsey, Alexander H. Reid, Mianzhen Mo, Duan Luo, Patrick Kramer, Xiaozhe Shen, Athavan Nadarajah, Alastair Stacey, Steven Prawer, Heather D. Whitley, Craig P. Schwartz, Richard J. Saykally","doi":"10.1021/acs.jpcc.4c05999","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05999","url":null,"abstract":"Structural details of the proposed solid–liquid phase transition of carbon have remained elusive, despite years of study. While it is theorized that novel carbon materials form from a liquid precursor, experimental studies have lacked the temporal and spatial resolution necessary to fully characterize the purported liquid state. Here we utilize megaelectronvolt-ultrafast electron diffraction (MeV-UED) to study laser irradiated submicron diamond thin films in a pump–probe scheme with picosecond time resolution to visualize potential structural changes of excited diamond. We probe the structure of diamond using a combination of fluences (13, 40 J/cm<sup>2</sup>) and time delays (10, 25, 100 ps), but observe negligible changes in the static diffraction pattern of diamond and an overall decrease in diffraction intensity up to 100 ps after the excitation pulse. We thus conclude that no appreciable amount of liquid or graphitized carbon is present and highlight the structural resilience of bulk diamond to intense 800 nm ultrafast laser pulses.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486589","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05167
Larisa R. Latypova, Irina N. Gracheva, Darya V. Shurtakova, Fadis F. Murzakhanov, Margarita A. Sadovnikova, Georgy V. Mamin, Marat R. Gafurov
NV– defects in silicon carbide (SiC) are emerging as a competitive alternative to NV– centers in diamond due to advanced industrial-scale SiC production methods. We present a study of the ground-state electron–nuclear coupling of negatively charged nitrogen-vacancy NV– centers in a 6H-SiC crystal by electron paramagnetic resonance and electron–nuclear double resonance techniques. The hyperfine and nuclear quadrupole interaction tensors have been precisely determined. The hyperfine coupling is found to be predominantly characterized by an isotropic contact Fermi part aiso = −1.125(2) MHz and a negligibly small dipole–dipole part b < 50 kHz. The nuclear quadrupole interaction is characterized by a coupling constant Cq = 2.530(3) MHz. The spin density distribution of the NVk2k1– center was calculated using density functional theory, and the theoretical electron–nuclear interaction values align well with experimental results. All established parameters are crucial for implementing NV– defects in SiC for quantum magnetometry, other sensing applications, and as robust qubits.
{"title":"Electron–Nuclear Interactions of NV Defects in an Isotopically Purified 6H-28SiC Crystal","authors":"Larisa R. Latypova, Irina N. Gracheva, Darya V. Shurtakova, Fadis F. Murzakhanov, Margarita A. Sadovnikova, Georgy V. Mamin, Marat R. Gafurov","doi":"10.1021/acs.jpcc.4c05167","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05167","url":null,"abstract":"NV<sup>–</sup> defects in silicon carbide (SiC) are emerging as a competitive alternative to NV<sup>–</sup> centers in diamond due to advanced industrial-scale SiC production methods. We present a study of the ground-state electron–nuclear coupling of negatively charged nitrogen-vacancy NV<sup>–</sup> centers in a 6<i>H</i>-SiC crystal by electron paramagnetic resonance and electron–nuclear double resonance techniques. The hyperfine and nuclear quadrupole interaction tensors have been precisely determined. The hyperfine coupling is found to be predominantly characterized by an isotropic contact Fermi part <i>a</i><sub><i>iso</i></sub> = −1.125(2) MHz and a negligibly small dipole–dipole part <i>b</i> < 50 kHz. The nuclear quadrupole interaction is characterized by a coupling constant <i>C</i><sub>q</sub> = 2.530(3) MHz. The spin density distribution of the NV<sub><i>k</i>2<i>k</i>1</sub><sup>–</sup> center was calculated using density functional theory, and the theoretical electron–nuclear interaction values align well with experimental results. All established parameters are crucial for implementing NV<sup>–</sup> defects in SiC for quantum magnetometry, other sensing applications, and as robust qubits.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486564","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c04822
Abdul Rehman, Robbert W.E. van de Kruijs, Wesley T.E. van den Beld, Jacobus M. Sturm, Marcelo Ackermann
Hydrogen is a crucial element in the green energy transition. However, its tendency to react with and diffuse into surrounding materials poses a significant challenge. Therefore, developing coatings to protect system components in hydrogen environments (molecular, radicals (H*), and plasma) is essential. In this work, we report group IV–V transition metal carbide (TMC) thin films as potential candidates for protective coatings in H* environments at elevated temperatures. We expose TiC, ZrC, HfC, VC, NbC, TaC, and Co2C thin films, with native surface oxycarbides/oxides (TMOxCy/TMOx), to H* at elevated temperatures. Based on X-ray photoelectron spectroscopy performed on the samples before and after H*-exposure, we identify three classes of TMCs. HfC, ZrC, TiC, TaC, NbC, and VC (class A) are found to have a stable carbidic-C (TM-C) content, with a further subdivision into partial (class A1: HfC, ZrC, and TiC) and strong (class A2: TaC, NbC, and VC) surface deoxidation. In contrast to class A, a strong carbide reduction is observed in Co2C (class B), along with a strong surface deoxidation. The H* interaction with TMC/TMOxCy/TMOx is hypothesized to entail three processes: (i) hydrogenation of surface C/O atoms, (ii) formation of CHx/OHx species, and (iii) subsurface C/O atom diffusion to the surface vacancies. The number of adsorbed H atoms required to form CHx/OHx species (i) and the corresponding thermodynamic energy barriers (ii) are estimated based on the change in the Gibbs free energy (ΔG) for the reduction reactions of TMCs and TMOx. Hydrogenation of surface carbidic-C atoms is proposed to limit the reduction of TMCs, whereas the deoxidation of TMC surfaces is governed by the thermodynamic energy barrier for forming H2O.
{"title":"Chemically Stable Group IV–V Transition Metal Carbide Thin Films in Hydrogen Radical Environments","authors":"Abdul Rehman, Robbert W.E. van de Kruijs, Wesley T.E. van den Beld, Jacobus M. Sturm, Marcelo Ackermann","doi":"10.1021/acs.jpcc.4c04822","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04822","url":null,"abstract":"Hydrogen is a crucial element in the green energy transition. However, its tendency to react with and diffuse into surrounding materials poses a significant challenge. Therefore, developing coatings to protect system components in hydrogen environments (molecular, radicals (H*), and plasma) is essential. In this work, we report group IV–V transition metal carbide (TMC) thin films as potential candidates for protective coatings in H* environments at elevated temperatures. We expose TiC, ZrC, HfC, VC, NbC, TaC, and Co<sub>2</sub>C thin films, with native surface oxycarbides/oxides (TMO<sub><i>x</i></sub>C<sub><i>y</i></sub>/TMO<sub><i>x</i></sub>), to H* at elevated temperatures. Based on X-ray photoelectron spectroscopy performed on the samples before and after H*-exposure, we identify three classes of TMCs. HfC, ZrC, TiC, TaC, NbC, and VC (class A) are found to have a stable carbidic-C (TM-C) content, with a further subdivision into partial (class A1: HfC, ZrC, and TiC) and strong (class A2: TaC, NbC, and VC) surface deoxidation. In contrast to class A, a strong carbide reduction is observed in Co<sub>2</sub>C (class B), along with a strong surface deoxidation. The H* interaction with TMC/TMO<sub><i>x</i></sub>C<sub><i>y</i></sub>/TMO<sub><i>x</i></sub> is hypothesized to entail three processes: (i) hydrogenation of surface C/O atoms, (ii) formation of CH<sub><i>x</i></sub>/OH<sub><i>x</i></sub> species, and (iii) subsurface C/O atom diffusion to the surface vacancies. The number of adsorbed H atoms required to form CH<sub><i>x</i></sub>/OH<sub><i>x</i></sub> species (i) and the corresponding thermodynamic energy barriers (ii) are estimated based on the change in the Gibbs free energy (Δ<i>G</i>) for the reduction reactions of TMCs and TMO<sub><i>x</i></sub>. Hydrogenation of surface carbidic-C atoms is proposed to limit the reduction of TMCs, whereas the deoxidation of TMC surfaces is governed by the thermodynamic energy barrier for forming H<sub>2</sub>O.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486469","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c03814
Hsin-Yun Chao, Adelaide M. Nolan, Alex T. Hall, Dmitri Golberg, Cheol Park, Wei-Chang David Yang, Yifei Mo, Renu Sharma, John Cumings
We present unprecedented results on the damage thresholds and pathways for boron nitride nanotubes (BNNT) under the influence of energetic electrons in an oxidative gas environment, using an environmental aberration-corrected electron microscope over a range of oxygen pressures. We observe a damage cascade process that resists damage until a higher electron dose, compared with carbon nanotubes, initiating at defect-free BNNT sidewalls and proceeding through the conversion from crystalline nanotubes to amorphous boron nitride (BN), resisting oxidation throughout. We compare with prior results on the oxidation of carbon nanotubes and present a model that attributes the onset of damage in both cases to a physisorbed oxygen layer that reduces the threshold for damage onset. Surprisingly, increased temperatures offer protection against damage, as do electron dose rates that significantly exceed the oxygen dose rates, and our model attributes both effects to a physisorbed oxygen population.
{"title":"Resistance of Boron Nitride Nanotubes to Radiation-Induced Oxidation","authors":"Hsin-Yun Chao, Adelaide M. Nolan, Alex T. Hall, Dmitri Golberg, Cheol Park, Wei-Chang David Yang, Yifei Mo, Renu Sharma, John Cumings","doi":"10.1021/acs.jpcc.4c03814","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c03814","url":null,"abstract":"We present unprecedented results on the damage thresholds and pathways for boron nitride nanotubes (BNNT) under the influence of energetic electrons in an oxidative gas environment, using an environmental aberration-corrected electron microscope over a range of oxygen pressures. We observe a damage cascade process that resists damage until a higher electron dose, compared with carbon nanotubes, initiating at defect-free BNNT sidewalls and proceeding through the conversion from crystalline nanotubes to amorphous boron nitride (BN), resisting oxidation throughout. We compare with prior results on the oxidation of carbon nanotubes and present a model that attributes the onset of damage in both cases to a physisorbed oxygen layer that reduces the threshold for damage onset. Surprisingly, increased temperatures offer protection against damage, as do electron dose rates that significantly exceed the oxygen dose rates, and our model attributes both effects to a physisorbed oxygen population.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486593","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05316
C. F. S. Codeço, S. L. A. Mello, G. M. Penello, B. F. Magnani, A. C. F. Santos, M. M. Sant’Anna
Synchrotron infrared nanospectroscopy (SINS) is used to study the effect of disorder on the phonon polariton in amorphous SiO2. For SiO2, it is known that the mid-infrared scattering spectrum is dominated by a surface phonon polariton mode associated with antisymmetric (AS) stretching. This excitation has a benchmark role in SINS studies. In this work, an amorphous 50 nm SiO2 film, on a crystalline Si(100) substrate, is irradiated with 25 keV fluorine anions and fluence of 1.3 × 1015 ions/cm2, modifying the two asymmetric stretches (AS1 and AS2) present in the SINS spectrum. The dominating peak corresponding to the SiO2 surface phonon polariton mode, AS1, has a maximum intensity that is affected by irradiation and shows a shoulder identified with a suboxide SiOx component (with x < 2) due to defects. On the other hand, the surface phonon polariton mode AS2 is completely suppressed by irradiation. In addition, calculations based on the finite dipole model (FDM) indicate that the polariton measured in the irradiated sample corresponds to the light–matter interaction at the surface of an effective medium combining the SiO2 and SiO regions.
{"title":"Tailoring Surface Phonon Polariton on SiO2 by Ion-Beam Irradiation","authors":"C. F. S. Codeço, S. L. A. Mello, G. M. Penello, B. F. Magnani, A. C. F. Santos, M. M. Sant’Anna","doi":"10.1021/acs.jpcc.4c05316","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05316","url":null,"abstract":"Synchrotron infrared nanospectroscopy (SINS) is used to study the effect of disorder on the phonon polariton in amorphous SiO<sub>2</sub>. For SiO<sub>2</sub>, it is known that the mid-infrared scattering spectrum is dominated by a surface phonon polariton mode associated with antisymmetric (AS) stretching. This excitation has a benchmark role in SINS studies. In this work, an amorphous 50 nm SiO<sub>2</sub> film, on a crystalline Si(100) substrate, is irradiated with 25 keV fluorine anions and fluence of 1.3 × 10<sup>15</sup> ions/cm<sup>2</sup>, modifying the two asymmetric stretches (AS<sub>1</sub> and AS<sub>2</sub>) present in the SINS spectrum. The dominating peak corresponding to the SiO<sub>2</sub> surface phonon polariton mode, AS<sub>1</sub>, has a maximum intensity that is affected by irradiation and shows a shoulder identified with a suboxide SiO<sub><i>x</i></sub> component (with <i>x</i> < 2) due to defects. On the other hand, the surface phonon polariton mode AS<sub>2</sub> is completely suppressed by irradiation. In addition, calculations based on the finite dipole model (FDM) indicate that the polariton measured in the irradiated sample corresponds to the light–matter interaction at the surface of an effective medium combining the SiO<sub>2</sub> and SiO regions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142487165","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c02395
Henry I. Eya, Nelson Y. Dzade
BaZrS3 has recently attracted significant attention as a cost-effective, high-stability, and eco-friendly solar absorber. The characteristics of BaZrS3-based solar cells in terms of power conversion efficiency and durability can be critically influenced by surface and interface properties inherent in the design and manufacture of these devices under ambient conditions. Herein, we present first-principles density functional theory (DFT) insights into the adsorption chemistry of oxygen and water on the three most stable (010), (100), and (111) surfaces of BaZrS3. We studied the underlying changes in the surface electronic structure, band gap, and work function in contact with oxygen and water. The Zr sites are found to be generally more reactive than Ba sites toward the adsorbing molecules. It was demonstrated that water interacts weakly with the BaZrS3 surfaces, whereas molecular and dissociative oxygen interact strongly with the BaZrS3 (010), (100), and (111) surfaces at the Zr sites. Charge density difference isosurfaces and Bader charge analyses reveal that the adsorption of oxygen is characterized by a significant charge transfer from the interacting surface species to the O2 molecule, resulting in the elongation of the O–O bonds, which was confirmed by vibrational frequency analysis. Unlike the case of oxygen, the dissociation of water is shown to be unfavorable, suggesting that water would preferentially exist as molecular water instead of dissociating to form hydroxylized (−OH) and sulfhydrylized (−SH) BaZrS3 surfaces. Projected density of states (PDOS) analyses reveal that while the naked (010) surface retained the intrinsic semiconducting nature of the bulk BaZrS3 with a suitable bandgap for optical applications, the creation of the (100) and (111) surfaces renders them semimetallic as the Fermi level marginally crosses the top of their valence bands. The adsorption of dissociated O2 and H2O species was found to enhance the semimetallic features of the three surfaces. Despite the introduction of semimetallic features, the surfaces possess a clear band gap as their valence bands do not overlap with their conduction bands. Relative to the naked BaZrS3 surfaces, we observed only small changes in the band gap and work function upon O2 and H2O adsorption, suggesting that their exposure to ambient conditions may not have a significant impact on their PV device performance. These results present new exciting opportunities for optimizing the electronic properties of BaZrS3 nanostructures for the fabrication of efficient and stable solar cell devices.
{"title":"First-Principles Investigation of Oxygen and Water Adsorption on (010), (100), and (111) Surfaces of BaZrS3 Chalcogenide Perovskite","authors":"Henry I. Eya, Nelson Y. Dzade","doi":"10.1021/acs.jpcc.4c02395","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c02395","url":null,"abstract":"BaZrS<sub>3</sub> has recently attracted significant attention as a cost-effective, high-stability, and eco-friendly solar absorber. The characteristics of BaZrS<sub>3</sub>-based solar cells in terms of power conversion efficiency and durability can be critically influenced by surface and interface properties inherent in the design and manufacture of these devices under ambient conditions. Herein, we present first-principles density functional theory (DFT) insights into the adsorption chemistry of oxygen and water on the three most stable (010), (100), and (111) surfaces of BaZrS<sub>3</sub>. We studied the underlying changes in the surface electronic structure, band gap, and work function in contact with oxygen and water. The Zr sites are found to be generally more reactive than Ba sites toward the adsorbing molecules. It was demonstrated that water interacts weakly with the BaZrS<sub>3</sub> surfaces, whereas molecular and dissociative oxygen interact strongly with the BaZrS<sub>3</sub> (010), (100), and (111) surfaces at the Zr sites. Charge density difference isosurfaces and Bader charge analyses reveal that the adsorption of oxygen is characterized by a significant charge transfer from the interacting surface species to the O<sub>2</sub> molecule, resulting in the elongation of the O–O bonds, which was confirmed by vibrational frequency analysis. Unlike the case of oxygen, the dissociation of water is shown to be unfavorable, suggesting that water would preferentially exist as molecular water instead of dissociating to form hydroxylized (−OH) and sulfhydrylized (−SH) BaZrS<sub>3</sub> surfaces. Projected density of states (PDOS) analyses reveal that while the naked (010) surface retained the intrinsic semiconducting nature of the bulk BaZrS<sub>3</sub> with a suitable bandgap for optical applications, the creation of the (100) and (111) surfaces renders them semimetallic as the Fermi level marginally crosses the top of their valence bands. The adsorption of dissociated O<sub>2</sub> and H<sub>2</sub>O species was found to enhance the semimetallic features of the three surfaces. Despite the introduction of semimetallic features, the surfaces possess a clear band gap as their valence bands do not overlap with their conduction bands. Relative to the naked BaZrS<sub>3</sub> surfaces, we observed only small changes in the band gap and work function upon O<sub>2</sub> and H<sub>2</sub>O adsorption, suggesting that their exposure to ambient conditions may not have a significant impact on their PV device performance. These results present new exciting opportunities for optimizing the electronic properties of BaZrS<sub>3</sub> nanostructures for the fabrication of efficient and stable solar cell devices.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486597","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05322
Stavros Athanasiou, Olivier J. F. Martin
Noble metals such as gold and silver have been used extensively for a range of plasmonic applications, including enhancing the fluorescence rate of a dye molecule, as evidenced by numerous experiments over the past two decades. Recently, a variety of doped semiconductors have been proposed as alternative plasmonic materials, exhibiting plasmonic resonances from ultraviolet to far-infrared. In this work, we investigate the suitability of these alternative materials for enhancing the fluorescence of a molecule. Considering nanosized spheres, we study their response under plane wave illumination and the resulting enhancement factors when coupled to a quantum emitter. Comparisons with standard plasmonic metals reveal that semiconductor materials lead to a significantly reduced, and often strongly quenched, emission of light caused by their dominant absorption, which hinders fluorescence enhancement. However, we show that enhancement may be obtained when considering poor emitting dyes and high refractive index environments. Our findings demonstrate that these alternative materials result in weaker fluorescence enhancement compared to their plasmonic counterparts. Nonetheless, there are means to compensate for this, and a reasonable enhancement can be achieved for dyes in the infrared spectrum.
{"title":"Alternative Plasmonic Materials for Fluorescence Enhancement","authors":"Stavros Athanasiou, Olivier J. F. Martin","doi":"10.1021/acs.jpcc.4c05322","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05322","url":null,"abstract":"Noble metals such as gold and silver have been used extensively for a range of plasmonic applications, including enhancing the fluorescence rate of a dye molecule, as evidenced by numerous experiments over the past two decades. Recently, a variety of doped semiconductors have been proposed as alternative plasmonic materials, exhibiting plasmonic resonances from ultraviolet to far-infrared. In this work, we investigate the suitability of these alternative materials for enhancing the fluorescence of a molecule. Considering nanosized spheres, we study their response under plane wave illumination and the resulting enhancement factors when coupled to a quantum emitter. Comparisons with standard plasmonic metals reveal that semiconductor materials lead to a significantly reduced, and often strongly quenched, emission of light caused by their dominant absorption, which hinders fluorescence enhancement. However, we show that enhancement may be obtained when considering poor emitting dyes and high refractive index environments. Our findings demonstrate that these alternative materials result in weaker fluorescence enhancement compared to their plasmonic counterparts. Nonetheless, there are means to compensate for this, and a reasonable enhancement can be achieved for dyes in the infrared spectrum.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486565","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05728
Manuel Matten, Thomas Lange, Markus Rohe, Bastian Mei, Sven Reichenberger, Stephan Barcikowski
Nanofunctionalized particles are widely used in heterogeneous catalysis, additive manufacturing, and environmental technologies. The electrostatically driven adsorption is an established method for the deposition of colloidal nanoparticles. It is described by the DLVO theory. Here, we investigated the adsorption efficiency and distribution of laser-generated colloidal Au nanoparticles (Au-NPs) on phase-pure and mixed-phase zinc sulfide (ZnS) under overall (apparent) electrostatic attraction and repulsion. For overall electrostatic attraction, a quantitative adsorption and uniform decoration of ZnS with Au-NPs was observed, consistent with the DLVO theory. However, under apparent electrostatic repulsion, 100 and 50% adsorption efficiency of Au-NPs on mixed-phase ZnS was observed despite an overall electrostatic energy barrier (assuming a uniform charge distribution) two to four times higher than the thermal diffusion energy of the Au-NPs, respectively. In contrast, phase-pure ZnS showed a significantly lower adsorption efficiency under similar conditions. Transmission electron microscopy (TEM) showed facet-selective adsorption in the case of apparent electrostatic repulsion with the Au-NPs preferentially binding to the edges of the wurtzite ZnS or the extended surfaces of mixed-phase ZnS. X-ray photoelectron spectroscopy (XPS) suggested that defects with different local surface charges may have served as attractive adsorption sites and need to be considered instead of only assuming overall repulsion as inferred when only comparing the respective ζ-potentials. Our results do not contradict the DLVO theory but infer the importance of considering local deviations of the ζ-potential, e.g., at different facets, extended or point defect clusters, especially when trying to predict the adsorption of colloidal, surfactant-free nanoparticles (e.g., from laser ablation in liquids) to mixed-phase systems under electrostatic repulsion. It also adds a new degree of freedom to potentially tailor nanoparticle-functionalized materials, where only specific local surface sites are being decorated with nanoparticles.
{"title":"Defect-Selective Energy Barrier Crossing during Adsorption of Colloidal Gold Nanoparticles on Zinc Sulfide Crystals under Overall Electrostatic Repulsion","authors":"Manuel Matten, Thomas Lange, Markus Rohe, Bastian Mei, Sven Reichenberger, Stephan Barcikowski","doi":"10.1021/acs.jpcc.4c05728","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05728","url":null,"abstract":"Nanofunctionalized particles are widely used in heterogeneous catalysis, additive manufacturing, and environmental technologies. The electrostatically driven adsorption is an established method for the deposition of colloidal nanoparticles. It is described by the DLVO theory. Here, we investigated the adsorption efficiency and distribution of laser-generated colloidal Au nanoparticles (Au-NPs) on phase-pure and mixed-phase zinc sulfide (ZnS) under overall (apparent) electrostatic attraction and repulsion. For overall electrostatic attraction, a quantitative adsorption and uniform decoration of ZnS with Au-NPs was observed, consistent with the DLVO theory. However, under apparent electrostatic repulsion, 100 and 50% adsorption efficiency of Au-NPs on mixed-phase ZnS was observed despite an overall electrostatic energy barrier (assuming a uniform charge distribution) two to four times higher than the thermal diffusion energy of the Au-NPs, respectively. In contrast, phase-pure ZnS showed a significantly lower adsorption efficiency under similar conditions. Transmission electron microscopy (TEM) showed facet-selective adsorption in the case of apparent electrostatic repulsion with the Au-NPs preferentially binding to the edges of the wurtzite ZnS or the extended surfaces of mixed-phase ZnS. X-ray photoelectron spectroscopy (XPS) suggested that defects with different local surface charges may have served as attractive adsorption sites and need to be considered instead of only assuming overall repulsion as inferred when only comparing the respective ζ-potentials. Our results do not contradict the DLVO theory but infer the importance of considering local deviations of the ζ-potential, e.g., at different facets, extended or point defect clusters, especially when trying to predict the adsorption of colloidal, surfactant-free nanoparticles (e.g., from laser ablation in liquids) to mixed-phase systems under electrostatic repulsion. It also adds a new degree of freedom to potentially tailor nanoparticle-functionalized materials, where only specific local surface sites are being decorated with nanoparticles.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486596","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 : 2024-10-22DOI: 10.1021/acs.jpcc.4c05486
Xin Zong, Fanghao Cheng, Yaru Dong, Sun Yin
Organic solar cells (OSCs) are lightweight, flexible, and highly transparent; however, their power conversion efficiency is currently subpar. This has motivated researchers to intensify their efforts to augment the performance of these devices. In non-fullerene-acceptor (NFA) OSCs, the impact of spin-triplet states has proved to be significant. In addition, it has been shown that the low exciton binding energies in NFAs, such as Y6, can lead to self-dissociation. These findings call for a deeper exploration. In this paper, we introduce an extended hot kinetic model that accounts for all spin states and the direct dissociation of local exciton states to evaluate their effects on OSC performance. The machine learning technique, specifically a regression neural network algorithm, is employed to handle the complex calculations related to the model. This algorithm generates the current density–voltage (J–V) curves for OSCs, from which three crucial factors are identified out of 28 examined factors, and their influence on the OSC performance parameters is thoroughly investigated. The analysis indicates that improving charge carrier mobility enhances the fill factor (FF), raising the energy of singlet charge transfer states increases the open-circuit voltage (VOC), and thicker film generally boosts short-circuit current density (JSC) but reduces the FF. Additionally, we explore how these three parameters affect device performance collectively. This research offers fresh insights into designing more efficient OSC devices.
{"title":"Identifying the Key Parameters for Organic Solar Cells Using the Machine Learning Method","authors":"Xin Zong, Fanghao Cheng, Yaru Dong, Sun Yin","doi":"10.1021/acs.jpcc.4c05486","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05486","url":null,"abstract":"Organic solar cells (OSCs) are lightweight, flexible, and highly transparent; however, their power conversion efficiency is currently subpar. This has motivated researchers to intensify their efforts to augment the performance of these devices. In non-fullerene-acceptor (NFA) OSCs, the impact of spin-triplet states has proved to be significant. In addition, it has been shown that the low exciton binding energies in NFAs, such as Y6, can lead to self-dissociation. These findings call for a deeper exploration. In this paper, we introduce an extended hot kinetic model that accounts for all spin states and the direct dissociation of local exciton states to evaluate their effects on OSC performance. The machine learning technique, specifically a regression neural network algorithm, is employed to handle the complex calculations related to the model. This algorithm generates the current density–voltage (<i>J</i>–<i>V</i>) curves for OSCs, from which three <i>crucial</i> factors are identified out of 28 examined factors, and their influence on the OSC performance parameters is thoroughly investigated. The analysis indicates that improving charge carrier mobility enhances the fill factor (FF), raising the energy of singlet charge transfer states increases the open-circuit voltage (<i>V</i><sub>OC</sub>), and thicker film generally boosts short-circuit current density (<i>J</i><sub>SC</sub>) but reduces the FF. Additionally, we explore how these three parameters affect device performance collectively. This research offers fresh insights into designing more efficient OSC devices.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142487124","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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