Pub Date : 2025-11-01Epub Date: 2025-07-10DOI: 10.1016/j.susc.2025.122807
A. Mizuhara , T. Fukuda , K. Umezawa
Silver-induced surface atomic structures on a Ni(110) surface up to 1 ML between room temperature and 673 K were studied using ultrahigh vacuum scanning tunneling microscopy and low-energy electron diffraction. A 0.72 ML-Ag-deposited surface at room temperature showed monolayer-high aggregated Ag stripes separated by periodic trenches and shallow troughs. Ag stripes consisted of six aggregated Ag atoms in the direction to form a one-dimensional (1-D) cluster and it extended in the direction with 3 × 9 and surface superstructures. Some Ag stripes were bridged by fuzzy regions where 1-D fluctuating Ag atoms were adsorbed on the substrate Ni(110) row. Above 473 K, the 1-D Ag cluster consisting of seven atoms formed Ag stripes with periodicity of the surface unit cell in the direction, and the Ni(110) substrate surface was exposed between the Ag stripes. The stability of the Ag stripes was confirmed by conducting first principles calculations and through simulated STM images.
{"title":"Initial stage of silver overlayer formation on the Ni(110) surface","authors":"A. Mizuhara , T. Fukuda , K. Umezawa","doi":"10.1016/j.susc.2025.122807","DOIUrl":"10.1016/j.susc.2025.122807","url":null,"abstract":"<div><div>Silver-induced surface atomic structures on a Ni(110) surface up to 1 ML between room temperature and 673 K were studied using ultrahigh vacuum scanning tunneling microscopy and low-energy electron diffraction. A 0.72 ML-Ag-deposited surface at room temperature showed monolayer-high aggregated Ag stripes separated by periodic trenches and shallow troughs. Ag stripes consisted of six aggregated Ag atoms in the <span><math><mrow><mo>[</mo><mn>1</mn><mover><mrow><mn>1</mn></mrow><mrow><mo>̄</mo></mrow></mover><mn>0</mn><mo>]</mo></mrow></math></span> direction to form a one-dimensional (1-D) cluster and it extended in the <span><math><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow></math></span> direction with 3 × 9 and <span><math><mfenced><mrow><mtable><mtr><mtd><mn>3</mn></mtd><mtd><mn>0</mn></mtd></mtr><mtr><mtd><mo>±</mo><mn>1</mn></mtd><mtd><mn>9</mn></mtd></mtr></mtable></mrow></mfenced></math></span> surface superstructures. Some Ag stripes were bridged by fuzzy regions where 1-D fluctuating Ag atoms were adsorbed on the substrate Ni(110) row. Above 473 K, the 1-D Ag cluster consisting of seven atoms formed Ag stripes with <span><math><mrow><mn>12</mn><mo>×</mo></mrow></math></span> periodicity of the surface unit cell in the <span><math><mrow><mo>[</mo><mn>1</mn><mover><mrow><mn>1</mn></mrow><mrow><mo>̄</mo></mrow></mover><mn>0</mn><mo>]</mo></mrow></math></span> direction, and the Ni(110) substrate surface was exposed between the Ag stripes. The stability of the Ag stripes was confirmed by conducting first principles calculations and through simulated STM images.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122807"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-08-04DOI: 10.1016/j.susc.2025.122814
Liujie Yang , Xiaolei Li , Tiantian Xu , Jiahao Yang , Tengfei Wang
This study investigates the adsorption and sensing properties of H-CrSe₂ monolayers doped with gold (Au) and silver (Ag) for detecting four toxic gases. First-principles calculations were performed to analyze the formation energy, structural changes, charge transfer, and density of states before and after gas adsorption. Meanwhile, molecular dynamics simulations at 300 K confirmed the stability of Ag/Au-CrSe₂ materials at room temperature. The results show that the adsorption energies of Ag/Au-CrSe₂ for these four gases range between 0.5 eV and 1.2 eV, indicating that the doping of Ag and Au atoms enhances the material's performance while preventing excessive adsorption that could lead to prolonged recovery times. Additionally, under 2 % biaxial tensile strain, the recovery times of Ag/Au-CrSe₂ for these four gases were significantly reduced to below 2 seconds. This study supports the application of H-CrSe₂ materials as gas sensors in environmental monitoring and industrial emission control.
本文研究了掺杂金（Au）和银（Ag）的H-CrSe₂单层膜对四种有毒气体的吸附和传感性能。利用第一性原理计算分析了气体吸附前后的地层能量、结构变化、电荷转移和态密度。同时，300 K下的分子动力学模拟证实了Ag/Au-CrSe 2材料在室温下的稳定性。结果表明，Ag/Au- crse 2对这四种气体的吸附能在0.5 eV ~ 1.2 eV之间，表明Ag和Au原子的掺杂提高了材料的性能，同时防止了过度吸附导致恢复时间延长。此外，在2%的双轴拉伸应变下，Ag/Au-CrSe 2对这四种气体的恢复时间显著缩短至2秒以下。本研究支持了H-CrSe₂材料作为气体传感器在环境监测和工业排放控制中的应用。
{"title":"Theoretical investigation of transition metal-doped CrSe₂ monolayer as a high-performance gas sensor for CO, SO₂, NO, and NO₂ detection","authors":"Liujie Yang , Xiaolei Li , Tiantian Xu , Jiahao Yang , Tengfei Wang","doi":"10.1016/j.susc.2025.122814","DOIUrl":"10.1016/j.susc.2025.122814","url":null,"abstract":"<div><div>This study investigates the adsorption and sensing properties of H-CrSe₂ monolayers doped with gold (Au) and silver (Ag) for detecting four toxic gases. First-principles calculations were performed to analyze the formation energy, structural changes, charge transfer, and density of states before and after gas adsorption. Meanwhile, molecular dynamics simulations at 300 K confirmed the stability of Ag/Au-CrSe₂ materials at room temperature. The results show that the adsorption energies of Ag/Au-CrSe₂ for these four gases range between 0.5 eV and 1.2 eV, indicating that the doping of Ag and Au atoms enhances the material's performance while preventing excessive adsorption that could lead to prolonged recovery times. Additionally, under 2 % biaxial tensile strain, the recovery times of Ag/Au-CrSe₂ for these four gases were significantly reduced to below 2 seconds. This study supports the application of H-CrSe₂ materials as gas sensors in environmental monitoring and industrial emission control.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122814"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-01DOI: 10.1016/j.susc.2025.122809
Hangqing Wu, Lu Yang, Liqun Wu, Xinning Li, Ruiyuan Li
In this study, we apply first-principle calculations to systematically investigate the synergistic regulation of physical properties of monolayer GeS materials by oxygen doping and biaxial strain. Theoretical calculations show that oxygen doping improves the charge uniformity of the system, and the strain enhancement reduces the degree of orbital hybridization and enhances the electron delocalization; doping broadens the bandgap of the material, which reaches a maximum at 2 % tensile strain, shrinks with increasing strain, and decreases monotonically under compressive strain. Differential charge density analysis shows that the tensile strain weakens the electronic reconfiguration of Ge-O bonds, reduces the bonding strength, and weakens the jump dipole moment; the compressive strain enhances the electron accumulation and orbital coupling, and improves the responsiveness of the material to low-energy light. The absorption spectra show that the biaxial strain decreases and blueshifts the absorption peaks, reflecting the broadening of the bandgap, while the compressive strain strengthens and redshifts the absorption peaks; in the reflectance spectra, the tensile strain diminishes the reflection peaks, while the compressive strain strengthens the reflection intensity. The study provides a theoretical basis for the energy band engineering of two-dimensional GeS materials as well as the application of flexible optoelectronic devices and tunable spectral sensors.
{"title":"Effect of applied biaxial strain in O-doped system on the optoelectronic properties of monolayer GeS","authors":"Hangqing Wu, Lu Yang, Liqun Wu, Xinning Li, Ruiyuan Li","doi":"10.1016/j.susc.2025.122809","DOIUrl":"10.1016/j.susc.2025.122809","url":null,"abstract":"<div><div>In this study, we apply first-principle calculations to systematically investigate the synergistic regulation of physical properties of monolayer GeS materials by oxygen doping and biaxial strain. Theoretical calculations show that oxygen doping improves the charge uniformity of the system, and the strain enhancement reduces the degree of orbital hybridization and enhances the electron delocalization; doping broadens the bandgap of the material, which reaches a maximum at 2 % tensile strain, shrinks with increasing strain, and decreases monotonically under compressive strain. Differential charge density analysis shows that the tensile strain weakens the electronic reconfiguration of Ge-O bonds, reduces the bonding strength, and weakens the jump dipole moment; the compressive strain enhances the electron accumulation and orbital coupling, and improves the responsiveness of the material to low-energy light. The absorption spectra show that the biaxial strain decreases and blueshifts the absorption peaks, reflecting the broadening of the bandgap, while the compressive strain strengthens and redshifts the absorption peaks; in the reflectance spectra, the tensile strain diminishes the reflection peaks, while the compressive strain strengthens the reflection intensity. The study provides a theoretical basis for the energy band engineering of two-dimensional GeS materials as well as the application of flexible optoelectronic devices and tunable spectral sensors.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122809"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-06DOI: 10.1016/j.susc.2025.122786
Mohammad Alif Arman , Edvin Lundgren , Jan Knudsen
The investigation of carbon monoxide (CO) adsorption on the unreconstructed Ir(100)-(1 × 1) surface under ultra-high vacuum (UHV) conditions is studied with scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and high-resolution core-level spectroscopy (HRCLS). At a low coverage of 0.5 ML (monolayer), CO molecules adopt a previously documented c(2 × 2) structure, having CO molecules adsorbed exclusively in the top sites. When the coverage increases to 0.83 ML, a c(6 × 2) phase is observed having a combination of bridge and top adsorption sites positions. A comprehensive picture of CO adsorption on Ir(100)-(1 × 1) is presented here by correlating the spectroscopic data with the observed distinct structural formations from STM and LEED.
{"title":"The low and high coverage adsorption structure of CO on unreconstructed Ir(100)-(1×1)","authors":"Mohammad Alif Arman , Edvin Lundgren , Jan Knudsen","doi":"10.1016/j.susc.2025.122786","DOIUrl":"10.1016/j.susc.2025.122786","url":null,"abstract":"<div><div>The investigation of carbon monoxide (CO) adsorption on the unreconstructed Ir(100)-(1 × 1) surface under ultra-high vacuum (UHV) conditions is studied with scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and high-resolution core-level spectroscopy (HRCLS). At a low coverage of 0.5 ML (monolayer), CO molecules adopt a previously documented c(2 × 2) structure, having CO molecules adsorbed exclusively in the top sites. When the coverage increases to 0.83 ML, a c(6 × 2) phase is observed having a combination of bridge and top adsorption sites positions. A comprehensive picture of CO adsorption on Ir(100)-(1 × 1) is presented here by correlating the spectroscopic data with the observed distinct structural formations from STM and LEED.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122786"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-21DOI: 10.1016/j.susc.2025.122813
Weiduo Wang
An in-depth understanding of the relationship between the structure and properties of physical vapor deposited (PVD) glass films is crucial for their applications at the nanoscale within industrial contexts. This study employs a coarse-grained simulation methodology to model PVD films composed of N,N-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) molecules with varying thicknesses. The findings indicate that, in contrast to liquid-quenched glasses (LQG), PVD glasses exhibit a higher elastic modulus and a lower loss modulus in the bulk, corroborating previous research that highlights enhanced mechanical stability. This work also shows that a region adjacent to the substrate of the PVD films has an exceptionally elevated elastic modulus that is correlated with changes in loss modulus, molecular orientation, and out-of-plane mobility. This phenomenon may be attributed to the surface-substrate effect resulting from the PVD process, and this effect may facilitate incoming molecule to a deeper energy state, resulting in a remarkable thermal and mechanical stability of ultrathin films.
{"title":"Interfacial effect on the formation and properties of stable glasses","authors":"Weiduo Wang","doi":"10.1016/j.susc.2025.122813","DOIUrl":"10.1016/j.susc.2025.122813","url":null,"abstract":"<div><div>An in-depth understanding of the relationship between the structure and properties of physical vapor deposited (PVD) glass films is crucial for their applications at the nanoscale within industrial contexts. This study employs a coarse-grained simulation methodology to model PVD films composed of N,N-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) molecules with varying thicknesses. The findings indicate that, in contrast to liquid-quenched glasses (LQG), PVD glasses exhibit a higher elastic modulus and a lower loss modulus in the bulk, corroborating previous research that highlights enhanced mechanical stability. This work also shows that a region adjacent to the substrate of the PVD films has an exceptionally elevated elastic modulus that is correlated with changes in loss modulus, molecular orientation, and out-of-plane mobility. This phenomenon may be attributed to the surface-substrate effect resulting from the PVD process, and this effect may facilitate incoming molecule to a deeper energy state, resulting in a remarkable thermal and mechanical stability of ultrathin films.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122813"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-01DOI: 10.1016/j.susc.2025.122790
Jianan Xie , Tao Lin , Cailin Wang
SiGe materials have become a research hotspot due to their important applications in semiconductor devices, especially in optoelectronic and high-speed electronic devices. In this study, based on molecular dynamics simulations, the influence of the Si buffer layer on the quality of films in Ge/Si/SiGe heterostructures is investigated. By simulating the growth process of the Ge/Si/SiGe heterostructure, a deposition model based on Ge(100) substrates is established. Inspired by the concept of reverse gradient buffer layers, Si buffer layers are directly grown on Ge substrates, followed by the deposition of SiGe films. This study primarily investigates the effects of the growth temperature and deposition thickness of the Si buffer layer on the quality of SiGe films. Based on the deposition parameters identified as suitable under the current simulation conditions (620 °C, 9.7 nm), the influence of the buffer layer on SiGe films with varying Ge compositions is further analyzed. The results show that the dislocations and stacking faults formed in the Si buffer layer effectively relieve the stress caused by lattice mismatch, thus improving the crystal quality of the subsequent SiGe films. This study provides theoretical insights into the Ge/Si/SiGe heterostructure film growth process, which helps enhance the quality of SiGe films and expands their applications in semiconductor devices.
{"title":"Influence of Si buffer layer on the crystal quality of SiGe films in Ge/Si/SiGe heterostructures: A molecular dynamics investigation","authors":"Jianan Xie , Tao Lin , Cailin Wang","doi":"10.1016/j.susc.2025.122790","DOIUrl":"10.1016/j.susc.2025.122790","url":null,"abstract":"<div><div>SiGe materials have become a research hotspot due to their important applications in semiconductor devices, especially in optoelectronic and high-speed electronic devices. In this study, based on molecular dynamics simulations, the influence of the Si buffer layer on the quality of films in Ge/Si/SiGe heterostructures is investigated. By simulating the growth process of the Ge/Si/SiGe heterostructure, a deposition model based on Ge(100) substrates is established. Inspired by the concept of reverse gradient buffer layers, Si buffer layers are directly grown on Ge substrates, followed by the deposition of SiGe films. This study primarily investigates the effects of the growth temperature and deposition thickness of the Si buffer layer on the quality of SiGe films. Based on the deposition parameters identified as suitable under the current simulation conditions (620 °C, 9.7 nm), the influence of the buffer layer on SiGe films with varying Ge compositions is further analyzed. The results show that the dislocations and stacking faults formed in the Si buffer layer effectively relieve the stress caused by lattice mismatch, thus improving the crystal quality of the subsequent SiGe films. This study provides theoretical insights into the Ge/Si/SiGe heterostructure film growth process, which helps enhance the quality of SiGe films and expands their applications in semiconductor devices.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122790"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-28DOI: 10.1016/j.susc.2025.122808
T. Stach , Md Arif Uddin , Uwe Burghaus , Trung T. Pham , Robert Sporken , Abdolvahab Seif , Alberto Ambrosetti , Pier Luigi Silvestrelli
Adsorption of ethyl ether, CH3CH2–O–CH2CH3 (or C4H10O or (CH3CH2)2O), on graphene/Si(111) (hereafter Gr/Si(111)) was characterized by kinetics (multi-mass thermal desorption spectroscopy (TDS), steady-state rate measurements) and spectroscopic (Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy) techniques as well as by density functional theory calculations (DFT) as a potential metal-free catalyst. TDS results agree with the expected fragmentation pattern of molecular ethyl ether. AES and XPS spectra collected after ethyl ether adsorption are identical with data for pristine Gr/Si(111). Therefore, ethyl ether adsorbs molecularly, consistent with large activation energies for dissociation calculated by the DFT.
通过动力学（多质量热解吸光谱（TDS）、稳态速率测量）、光谱（埃格电子能谱（AES）、x射线光电子能谱（XPS）、拉曼光谱）技术以及密度泛函理论计算（DFT），表征了乙醚CH3CH2 - o - ch2ch3（或C4H10O或（CH3CH2）2O）在石墨烯/Si(111)（以下简称Gr/Si(111)）上作为潜在无金属催化剂的吸附特性。TDS结果与预期的乙醚分子断裂模式一致。乙醚吸附后收集的AES和XPS光谱与原始Gr/Si（111）的数据一致。因此，乙醚在分子上吸附，这与DFT计算的解离活化能大一致。
{"title":"Adsorption of ethyl ether on graphene/silicon – Theory and experiment","authors":"T. Stach , Md Arif Uddin , Uwe Burghaus , Trung T. Pham , Robert Sporken , Abdolvahab Seif , Alberto Ambrosetti , Pier Luigi Silvestrelli","doi":"10.1016/j.susc.2025.122808","DOIUrl":"10.1016/j.susc.2025.122808","url":null,"abstract":"<div><div>Adsorption of ethyl ether, CH<sub>3</sub>CH<sub>2</sub>–O–CH<sub>2</sub>CH<sub>3</sub> (or C<sub>4</sub>H<sub>10</sub>O or (CH<sub>3</sub>CH<sub>2</sub>)<sub>2</sub>O), on graphene/Si(111) (hereafter Gr/Si(111)) was characterized by kinetics (multi-mass thermal desorption spectroscopy (TDS), steady-state rate measurements) and spectroscopic (Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy) techniques as well as by density functional theory calculations (DFT) as a potential metal-free catalyst. TDS results agree with the expected fragmentation pattern of molecular ethyl ether. AES and XPS spectra collected after ethyl ether adsorption are identical with data for pristine Gr/Si(111). Therefore, ethyl ether adsorbs molecularly, consistent with large activation energies for dissociation calculated by the DFT.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122808"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-06-28DOI: 10.1016/j.susc.2025.122803
Andreas Riemann, Lauren Rankin, Dylan Henry
In this study we have systematically investigated the adsorption geometries and energies of various merocyanine/spiropyran molecules on NaCl. The molecules are closed-ring spiropyran molecules with various side groups which can be transferred into open-ring merocyanine molecules. These isomers act as molecular switches which can be triggered by different external stimuli. The underlying substrate for this study is a two-layer film of the ionic insulator sodium chloride (NaCl). Adsorption of the spiropyran molecules is mostly driven by a competition between the sets of aromatic rings being able to find configurations close to the surface which leads overall to more preferable adsorption energies. On the other hand, since the merocyanine isomer as T-conformers have a generally flat geometry, they will be able to orient themselves nearly parallel to the substrate. This leads to higher binding energies for T-conformer compared to C-conformers, which due to steric effects cannot adsorb in a flat configuration. The beginning of film growth for these molecules starts with dimer formation which can be in parallel or anti-parallel geometries. In general, the anti-parallel configurations lead to higher binding energies when oppositely charged moieties of the molecules can interact through Coulomb forces. Comparing the calculated dimer configurations to experimentally observed dimers allows us to identify the particular conformers for each merocyanine molecule which might be energetically more favorable upon adsorption on the substrate. For two molecules with similar side groups, namely benzo and naphtho merocyanine, the so-called CTT and TTC conformers form dimers with highest binding energies, whereas for nitro and methoxy merocyanine, which have a common nitro side group, the dimers with highest binding energies consist of CTC and TTT conformers.
{"title":"Dimer adsorption and identification for various spiropyran-based molecular switches using Molecular Mechanics calculations","authors":"Andreas Riemann, Lauren Rankin, Dylan Henry","doi":"10.1016/j.susc.2025.122803","DOIUrl":"10.1016/j.susc.2025.122803","url":null,"abstract":"<div><div>In this study we have systematically investigated the adsorption geometries and energies of various merocyanine/spiropyran molecules on NaCl. The molecules are closed-ring spiropyran molecules with various side groups which can be transferred into open-ring merocyanine molecules. These isomers act as molecular switches which can be triggered by different external stimuli. The underlying substrate for this study is a two-layer film of the ionic insulator sodium chloride (NaCl). Adsorption of the spiropyran molecules is mostly driven by a competition between the sets of aromatic rings being able to find configurations close to the surface which leads overall to more preferable adsorption energies. On the other hand, since the merocyanine isomer as T-conformers have a generally flat geometry, they will be able to orient themselves nearly parallel to the substrate. This leads to higher binding energies for T-conformer compared to C-conformers, which due to steric effects cannot adsorb in a flat configuration. The beginning of film growth for these molecules starts with dimer formation which can be in parallel or anti-parallel geometries. In general, the anti-parallel configurations lead to higher binding energies when oppositely charged moieties of the molecules can interact through Coulomb forces. Comparing the calculated dimer configurations to experimentally observed dimers allows us to identify the particular conformers for each merocyanine molecule which might be energetically more favorable upon adsorption on the substrate. For two molecules with similar side groups, namely benzo and naphtho merocyanine, the so-called CTT and TTC conformers form dimers with highest binding energies, whereas for nitro and methoxy merocyanine, which have a common nitro side group, the dimers with highest binding energies consist of CTC and TTT conformers.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122803"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144521545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-09DOI: 10.1016/j.susc.2025.122811
Matteo Cargnello , Sen Zhang
{"title":"Well-defined nanoparticles: synthesis, characterization, applications in the XXI century (Surface Science special issue)","authors":"Matteo Cargnello , Sen Zhang","doi":"10.1016/j.susc.2025.122811","DOIUrl":"10.1016/j.susc.2025.122811","url":null,"abstract":"","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122811"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-07-04DOI: 10.1016/j.susc.2025.122810
Om Shree Rijal, Hari Krishna Neupane, Pitamber Shrestha, Shriram Sharma, Leela Pradhan Joshi, Rajendra Parajuli
The present work investigates the structural, electronic, and magnetic properties of a (3 × 3 × 1) supercell monolayer of Mn doped ZnO (Mn-ZnO), CO adsorbed on ZnO (CO-ZnO), NH3 adsorbed on ZnO (NH3-ZnO), and CO & NH3 adsorbed on Mn-ZnO (CO-Mn-ZnO, & NH3−Mn-ZnO) structures. Density functional theory (DFT) method with a projected augmented basis set has been used for this study, by employing two different exchange-correlation functionals: GGA-PBE and GGA-PBE+U through the Vienna-Ab-intio Simulation Package (VASP) software. We analyzed the lattice parameters, which reveal that doping Mn into ZnO, and adsorbing NH3 and CO molecules on both ZnO and Mn-ZnO result in changes to the lattice parameters. Thus, the adsorbed molecules alter the lattice parameters, suggesting that both ZnO and Mn-ZnO have the ability to detect poisonous gases. Moreover, we also studied the band gap energy of considered materials using two functionals, PBE and PBE+U. The obtained band gap energies are closer to the experimental values when applying the PBE+U functional. Lastly, pristine ZnO, as well as CO, and NH3 adsorbed ZnO (CO-ZnO, & NH3-ZnO), are found to be non-magnetic, whereas Mn-ZnO, along with CO, and NH3 adsorbed Mn-ZnO (CO-Mn-ZnO, & NH3−Mn-ZnO) are found to be magnetic. Based on electronic and magnetic properties, considered materials are suited for sensing devices.
{"title":"First-principles study on the adsorption behavior of ZnO and Mn-doped ZnO with CO and NH3 gases","authors":"Om Shree Rijal, Hari Krishna Neupane, Pitamber Shrestha, Shriram Sharma, Leela Pradhan Joshi, Rajendra Parajuli","doi":"10.1016/j.susc.2025.122810","DOIUrl":"10.1016/j.susc.2025.122810","url":null,"abstract":"<div><div>The present work investigates the structural, electronic, and magnetic properties of a (3 × 3 × 1) supercell monolayer of Mn doped ZnO (Mn-ZnO), CO adsorbed on ZnO (CO-ZnO), NH<sub>3</sub> adsorbed on ZnO (NH<sub>3</sub>-ZnO), and CO & NH<sub>3</sub> adsorbed on Mn-ZnO (CO-Mn-ZnO, & NH<sub>3</sub>−Mn-ZnO) structures. Density functional theory (DFT) method with a projected augmented basis set has been used for this study, by employing two different exchange-correlation functionals: GGA-PBE and GGA-PBE+<em>U</em> through the Vienna-Ab-intio Simulation Package (VASP) software. We analyzed the lattice parameters, which reveal that doping Mn into ZnO, and adsorbing NH<sub>3</sub> and CO molecules on both ZnO and Mn-ZnO result in changes to the lattice parameters. Thus, the adsorbed molecules alter the lattice parameters, suggesting that both ZnO and Mn-ZnO have the ability to detect poisonous gases. Moreover, we also studied the band gap energy of considered materials using two functionals, PBE and PBE+<em>U</em>. The obtained band gap energies are closer to the experimental values when applying the PBE+<em>U</em> functional. Lastly, pristine ZnO, as well as CO, and NH<sub>3</sub> adsorbed ZnO (CO-ZnO, & NH<sub>3</sub>-ZnO), are found to be non-magnetic, whereas Mn-ZnO, along with CO, and NH<sub>3</sub> adsorbed Mn-ZnO (CO-Mn-ZnO, & NH<sub>3</sub>−Mn-ZnO) are found to be magnetic. Based on electronic and magnetic properties, considered materials are suited for sensing devices.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122810"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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