Physica E-low-dimensional Systems & Nanostructures最新文献

{"title":"Realization of the novel optical absorption device with broadened bandwidth based on the multi-layered doped nanofilm structures","authors":"Lin Zhao ,&nbsp;Jiaxin Li ,&nbsp;Huaning Wu","doi":"10.1016/j.physe.2025.116195","DOIUrl":"10.1016/j.physe.2025.116195","url":null,"abstract":"<div><div>The demand for optical absorption devices with high efficiency and wide bandwidth is rising. However, current methods like CPA and ENZ media with lossy dopants achieve perfect absorption only at specific frequencies or very narrow bands, limiting their broader use.Thus, broadening the operating bandwidth of high absorption is crucial for designing high-performance optical absorption devices. In this study, the relationship between the number of dopants and the resonant bandwidth of the doped ENZ medium structure was thoroughly analyzed. The results thus obtained show that the resonant bandwidth of the whole structure significantly widened as the number of dopants increased, thus expanding the bandwidth of high absorption of this structure. In addition, a multi-layer Ag/SiC nanofilm structure filled with dopants was used to design a light absorption device insensitive to the angle of incidence, achieving nearly 100 % absorption efficiency at a wavelength of 430 nm with a good working bandwidth.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116195"},"PeriodicalIF":2.9,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Janus HfMCO2 (M= Cr, Mo, Fe, Nb, Sc, Ta, Ti, V, W, Y and Zr) MXene: Promising candidates for electrode of supercapacitor","authors":"Rui-Zhou Zhang ,&nbsp;Xiao-Hong Li ,&nbsp;Hong-Ling Cui","doi":"10.1016/j.physe.2025.116196","DOIUrl":"10.1016/j.physe.2025.116196","url":null,"abstract":"<div><div>Janus MXenes have received greater attention for their outstanding properties. The electronic and optical properties, effective mass and quantum capacitance of Janus HfMCO₂ (M = Cr, Mo, Fe, Nb, Sc, Ta, Ti, V, W, Y and Zr) are investigated by using first-principles calculation with HSE06 functional. HfMCO₂ (M = Cr, Fe, V, Y) are magnetic semiconductors. The doping of Mo, Nb, Sc, Ta, and W atoms induces the transition of Hf₂CO₂ from semiconductor to metal. HfCrCO₂, HfScCO₂, and HfVCO₂ have stronger magnetism with magnetic moments. The significant larger m_h∗ of HfFeCO₂ indicates the smaller hole mobility in valence band and slow diffusion. The optical analysis indicates that all the systems except HfVCO₂ have better conductivity than Hf₂CO₂, especially for HfWCO₂ with <em>ε</em>₁(0) of 14.08. The doping of Fe, Ti, Mo, W and Zr atoms drastically increases the absorption coefficient in infrared and visible regions. Janus HfMCO₂ (M = Cr, Fe, Mo, Sc, Ti, V, W and Zr) are suitable for cathode electrode, while HfTaCO₂ and HfYCO₂ are suitable for symmetrical electrode material. Large voltage only changes the electrode types of HfWCO₂ and HfYCO₂ to symmetric and cathode electrodes, respectively. The electrode type of Janus HfMCO₂ having mixed terminations are analyzed.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116196"},"PeriodicalIF":2.9,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of screening on seebeck coefficient in bilayer graphene/AlGaAs electron gas","authors":"Vo Van Tai ,&nbsp;Nguyen Duy Vy ,&nbsp;Truong Van Tuan ,&nbsp;Nguyen Quoc Khanh","doi":"10.1016/j.physe.2025.116194","DOIUrl":"10.1016/j.physe.2025.116194","url":null,"abstract":"<div><div>The knowledge of Seebeck coefficient is a key factor in optimization of thermoelectric materials and finding right applications for it. A high sensitivity to structural change makes thermopower measurements an excellent technique for the study on the charge transport properties of a given material. The phonon-drag term dominates at low temperature in the Seebeck coefficient. This study examines the temperature-dependent screening effect on the phonon-drag-induced Seebeck coefficient (<span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span>) in a bilayer graphene (BLG)-AlGaAs/quasi-two-dimensional electron gas (q2DEG) system at the temperature below 50 K. The BLG layer interacts with both deformation potential acoustic phonons and stronger piezoelectric field acoustic phonons from AlGaAs/GaAs. We compare the electron–phonon interactions in BLG with and without screening by q2DEG. The screening effect reduces <span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span>, particularly at low temperatures, and shows a strong dependence on the carrier density in the BLG layer. The double-layer screening function increases <span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span> with layer separation (d), paralleling the monolayer screening at large d. Additionally, varying the GaAs quantum well width reveals that <span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span> increases with width less than 100 Å under double-layer screening but remains unchanged beyond this threshold, while monolayer screening decreases <span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span> as the width increases. Both screening functions enhance <span><math><mrow><msup><mi>S</mi><mi>g</mi></msup></mrow></math></span> when the BLG carrier density is lower than that of q2DEG, though the magnitude difference between them is minimal.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116194"},"PeriodicalIF":2.9,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-dimensional GaN of wurtzite、hexagonal and haeckelite (4|8) structure with multiple layers: A first principle DFT study on structural and optoelectronic properties","authors":"Yuting Dai ,&nbsp;Sihao Xia ,&nbsp;Hongkai Shi ,&nbsp;Yuyan Wang ,&nbsp;Xian Wu ,&nbsp;Yu Diao","doi":"10.1016/j.physe.2025.116193","DOIUrl":"10.1016/j.physe.2025.116193","url":null,"abstract":"<div><div>This study aims to investigate the optoelectronic properties of three different structures of two-dimensional GaN, namely wurtzite, hexagonal, and haeckelite, through first-principles calculations. The goal is to provide a theoretical foundation for the design and development of high-performance optoelectronic devices. As a new type of semiconductor material, two-dimensional GaN has attracted much attention due to its excellent optoelectronic properties. In our study, we found that as the layer thickness increases, the optimal structure of two-dimensional GaN transitions from the hexagonal phase to the haeckelite phase, and finally stabilizes in the wurtzite structure. During this process, the work function continuously increases and tends to stabilize, with the wurtzite structure's work function eventually stabilizing at 5.50 eV, while the work functions of the hexagonal and haeckelite (4|8) structures stabilize around 7.35 eV. The wurtzite structure exhibits a significantly enhanced internal electric field between layers, whereas the hexagonal and haeckelite structures do not show interlayer polarization due to the coincidence of positive and negative charge centers. Compared to bulk materials, two-dimensional GaN shows a larger bandgap, which gradually decreases with increasing layer thickness and tends to stabilize at around 10 layers. The hexagonal structure has the largest bandgap, while the wurtzite and haeckelite structures have relatively smaller bandgaps. Specifically, the bandgap of the wurtzite structure decreases from 5 eV for a single layer to approximately 1.50 eV at around 10 layers. The hexagonal structure exhibits the largest bandgap of 2.61 eV at 5 layers, stabilizing at around 2.60 eV at 10 layers. The haeckelite structure's bandgap decreases from 2.71 eV at 5 layers to 1.61 eV at 15 layers. The valence band maximum is primarily contributed by the p-states of nitrogen and gallium, while the conduction band minimum originates from the hybridization of the s-orbitals of nitrogen and gallium. Additionally, the effective mass continuously decreases with increasing layer thickness, with the haeckelite structure showing the highest effective mass of 0.97m₀ at a single layer, reducing to 0.27m₀ at 15 layers. Our research also examined the optical properties of these three structures, providing a comprehensive understanding of the optoelectronic performance of two-dimensional GaN. These findings not only reveal the relationship between the structure and properties of two-dimensional GaN but also offer important references for future applications in the field of solid-state optoelectronics.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116193"},"PeriodicalIF":2.9,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating transition metal (Fe, Co, Ni)-doped biphenylene network as a sensor for SF6 decomposition molecules detection at the atomic scale","authors":"Jia-Yao Yuan ,&nbsp;Zhi-Gang Shao","doi":"10.1016/j.physe.2025.116178","DOIUrl":"10.1016/j.physe.2025.116178","url":null,"abstract":"<div><div>For the detection of SF₆ decomposition products, the development of high performance sensor materials is extremely critical. Biphenylene network (BPN), an emerging 2D carbon material, shows great potential in gas sensing. However, pristine BPN has limited performance in detecting SF₆ decomposition products, and doping strategies are required to optimize its sensing performance. The adsorption mechanism and gas-sensitive properties of three transition metal-doped biphenylene network (TM-BPN) on SF₆ decomposition products (SO₂ and H₂S) are investigated using first-principle calculations. After identifying the most stable doping sites, the correlation adsorption calculations show a significant charge transfer between TM-BPN and SO₂, accompanied by the formation of covalent bonds. Among them, the adsorption energy of Fe-BPN on SO₂ is −1.308 eV, which shows strong chemisorption. At the optimum operating temperature, the Fe-BPN system has a fast recovery time of 15.5 s, a high change of the work function of about 1 eV, and a strong resistivity change. So this gas-sensitive material is well suited for detecting SO₂ molecules. The computational results in this paper provide theoretical guidance for advancing the development of BPN as a high-sensitivity gas sensor for electrical insulation equipment.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116178"},"PeriodicalIF":2.9,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable fano-like resonances in graphene metasurface for quad-frequency optoelectronic sensing","authors":"Mingfei Wang ,&nbsp;Wei Cui ,&nbsp;Yixuan Wang ,&nbsp;Mengyao Li ,&nbsp;Xin Qie","doi":"10.1016/j.physe.2025.116191","DOIUrl":"10.1016/j.physe.2025.116191","url":null,"abstract":"<div><div>To address the increasing demands in optoelectronic sensing technologies, we propose a novel patterned graphene-based metasurface with tunable electromagnetic properties, tailored for advanced sensing applications. Finite-Difference Time-Domain (FDTD) simulations are employed to design and analyze the metasurface under terahertz excitation, enabling the modulation of double and triple Fano-like resonances by adjusting structural parameters, Fermi levels, and carrier mobility. Bright-dark mode theory and electric field distribution analyses provide insights into the underlying resonance mechanisms. Furthermore, the metasurface demonstrates high sensitivity in cholesterol concentration detection, achieving a maximum sensitivity of 1.8424 THz/RIU and a figure of merit (FOM) of 44.27. Notably, the graphene metasurface supports quad-frequency sensing, showcasing its potential for precise environmental monitoring and tunable optoelectronic device applications.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116191"},"PeriodicalIF":2.9,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valley-dependent electronic transport in a graphene with double magnetic-strained barriers","authors":"Man-Ting Li,&nbsp;Yang-Lai Hou,&nbsp;Jian-Duo Lu,&nbsp;Jin-Ze Ye,&nbsp;Jing Huang","doi":"10.1016/j.physe.2025.116176","DOIUrl":"10.1016/j.physe.2025.116176","url":null,"abstract":"<div><div>Using the transfer-matrix method, we investigate the valley-dependent electronic transport in a graphene with double magnetic-strained barriers. The effects of the magnitude, position and width of the strained barriers as well as the strength of the magnetic field on the electronic conductance and the valley polarization in the parallel (P) configuration are analyzed. In order to comprehensively understand and apply this model, we also study how the strength of the magnetic field and the magnitude of the strained barriers affect the valley polarization when the ferromagnetic metal (FM) stripes are shifted from P configuration to antiparallel (AP) configuration. The results show that the magnetic field and the strains significantly influence the electronic transport properties in both P and AP configurations. Therefore, this work provides crucial help for understanding valley-dependent transport characteristics, and the studied graphene nanostructure is useful for designing the valleytronic device.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116176"},"PeriodicalIF":2.9,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoelectric properties of a correlated polar single molecular transistor in the presence of a magnetic field and dissipation","authors":"Pooja Saini ,&nbsp;Manasa Kalla ,&nbsp;Soma Mukhopadyay ,&nbsp;Ashok Chatterjee ,&nbsp;I. Yu Popov","doi":"10.1016/j.physe.2024.116175","DOIUrl":"10.1016/j.physe.2024.116175","url":null,"abstract":"<div><div>The spin Seebeck effect is investigated in a correlated polar single molecular transistor in the presence of dissipation and a magnetic field. The Anderson-Holstein-Caldeira-Leggett model is used to study the heat transport characteristics of the system. Assuming the phonons to be in the coherent state, the effective electronic Hamiltonian is solved using the Keldysh method. The spectral function, conductance, spin Seebeck effect, and spin-polarized current densities are calculated. As the magnetic field increases, the charge conductance splits into two symmetric peaks, while the spin conductance separates into two antisymmetric peaks. In the absence of a magnetic field, only the charge conductance and Seebeck coefficient are maximum, while the spin conductance and spin Seebeck coefficient remain zero. However, as the magnetic field increases, both spin conductance and spin Seebeck coefficient undergo an enhancement. We also observe a substantial enhancement in the thermopower with the increase in the electron-phonon coupling.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116175"},"PeriodicalIF":2.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous tuning of band gap by strain engineering in new predicted 13H-Si allotrope","authors":"Teng Wan ,&nbsp;Qingyang Fan ,&nbsp;Dangli Gao ,&nbsp;Ruida Zhao ,&nbsp;Sining Yun","doi":"10.1016/j.physe.2025.116177","DOIUrl":"10.1016/j.physe.2025.116177","url":null,"abstract":"<div><div>Diamond silicon and most of its allotropes have indirect band gaps that do not allow electrons to propagate directly between the valence and conduction band edges due to momentum mismatch, limiting their performance and efficiency in optoelectronic devices. With the rapid development of the optoelectronic industry, searching for new silicon allotropes with adjustable and/or direct band gap has become increasingly urgent. Here, we predict five new silicon allotropes 13H-Si with continuously tunable band gap, high mechanical, dynamic and thermal stability under tensile strain. As expected, besides their adjustable band gaps in a wide range (0.80–1.30 eV), the indirect-to-direct band gap transition can be achieved in these predicted silicon allotrope 13H-Si under tensile strain (4.5–9.0 %) along <em>a-</em> and <em>b-</em>axis. Especially, these predicted 13H-Si not only demonstrate the stronger visible light absorption ability than diamond silicon, but also show the enhanced absorption intensity under axial strain. The current research not only enriches the types of silicon allotropes, but also accumulates data for the application of silicon materials in the field of solar photovoltaics.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116177"},"PeriodicalIF":2.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrical contact between 2D material NbS2 and WSSe","authors":"Jingjun Chen,&nbsp;Zelong Ma,&nbsp;Danni Wang,&nbsp;Xu Li,&nbsp;Songyang Li,&nbsp;Baoan Bian","doi":"10.1016/j.physe.2025.116179","DOIUrl":"10.1016/j.physe.2025.116179","url":null,"abstract":"<div><div>Achieving Ohmic contact at the metal-semiconductor interface is a key technological issue for miniaturization and high performance of nanoelectronic devices. In this study, we design a metal-semiconductor heterostructure consisting of cold metal NbS₂ and semiconductor WSSe, and study the properties of the electric contact by first-principles calculations. SWSe/NbS₂ and SeWS/NbS₂ both show p-type Schottky contact with different Schottky barrier heights and high charge injection efficiency. The heterojunctions can achieve the Ohmic contacts under the modulation of the interlayer distance, strain and electric field. In addition, the electric field causes changed contact type from p-type Schottky contact to n-type Schottky contact for both heterojunctions. Different interface contact for WSSe/NbS₂ induces different electronic properties. The results provide the theoretical guidance for the application of WSSe/NbS₂ heterojunction in the development of next-generation electronic and optoelectronic devices.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"168 ","pages":"Article 116179"},"PeriodicalIF":2.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}