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

{"title":"The regulation of interface defects and photovoltaic performances of PbS/MAPbI3 core-shell nanorod arrays by quantum dot ligand","authors":"Peng Ye ,&nbsp;Yahong Wang ,&nbsp;Luming Zhou,&nbsp;Junying Yu,&nbsp;Lin He,&nbsp;Rongli Gao,&nbsp;Chunlin Fu","doi":"10.1016/j.physe.2025.116420","DOIUrl":"10.1016/j.physe.2025.116420","url":null,"abstract":"<div><div>The PbS quantum dots/MAPbI₃ core-shell nanorod array improves the photovoltaic performance by expanding the solar spectral absorption range and optimizing the carrier transport path, but the serious non-radiative recombination restriction efficiency caused by quantum dot/perovskite interface defects breaks through. Ligand modification is an effective post-processing strategy to passivate quantum dot defects. The MA⁺ and Pb²⁺ in the halogen ligand can be used as the intrinsic components of the perovskite and form hydrogen bonds with MAPbI₃ in situ, the short-chain characteristics eliminate the insulating barrier of the oleic acid ligand and increase the carrier mobility. In this paper, methylammonium iodide (MAI) and lead iodide (PbI₂) were used as passivators for the composite interface of nanorod arrays to explore the effects of different ligands on the composite interface, especially on perovskite. The results show that the MAI ligand system improves the interface defects of the infrared quantum dot/perovskite composite more prominently than the PbI₂ system. MA⁺ promotes the order of perovskite crystal orientation, improves the morphology, reduces the trap state, and improves the final photovoltaic conversion efficiency by 36 %. This work provides a new paradigm for the regulation of interface defects in PbS/MAPbI₃ composite solar cells through ligand chemical bond coordination strategy.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"177 ","pages":"Article 116420"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145600507","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":"Study of linear and nonlinear absorption and refractive index changes in multilayered spherical quantum dots for various excited states","authors":"A. Fakkahi ,&nbsp;Frankbelson dos S. Azevedo ,&nbsp;H. Azmi ,&nbsp;M. Jaouane ,&nbsp;J. El-Hamouchi ,&nbsp;A. Sali ,&nbsp;A. Ed-Dahmouny ,&nbsp;K. El-Bakkari ,&nbsp;R. Arraoui ,&nbsp;A. Mazouz ,&nbsp;M. Jaafar","doi":"10.1016/j.physe.2025.116445","DOIUrl":"10.1016/j.physe.2025.116445","url":null,"abstract":"<div><div>This study investigates the linear and nonlinear optical properties of multilayered spherical quantum dots by focusing on electronic transitions between the <span><math><mrow><mi>s</mi><mo>→</mo><mi>p</mi></mrow></math></span>, <span><math><mrow><mi>p</mi><mo>→</mo><mi>d</mi></mrow></math></span>, and <span><math><mrow><mi>d</mi><mo>→</mo><mi>f</mi></mrow></math></span> states. Using the Finite Element Method (FEM) within the Effective Mass Approximation (EMA), we calculate the linear, third-order nonlinear, and total optical absorption coefficients, as well as the corresponding changes in the refractive index. Our results reveal distinct spectral features associated with each type of transition, highlighting the influence of quantum confinement on the absorption and refractive index behavior. In particular, we find that the nonlinear optical response becomes increasingly significant for higher excited-state transitions, where the third-order nonlinear absorption may surpass the linear contribution in the vicinity of resonance. This behavior is observed across multiple excitation pathways, indicating that the dominance of nonlinear effects may be a general feature associated with transitions involving larger spatial extension of the electronic wavefunctions. The interplay between these transitions governs the overall optical response of the quantum dots, providing insight into their potential applications in optoelectronic and nanophotonic devices. These results suggest that multilayered spherical quantum dots can be engineered to selectively enhance nonlinear optical processes, making them promising candidates for the development of tunable, intensity-dependent photonic components.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"177 ","pages":"Article 116445"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840169","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":"Cobalt-induced Multifunctionality: Ferromagnetism and tunable optoelectronic properties in hydrothermally synthesized SnS2 nanoparticles","authors":"Anjali Bhattacharyya,&nbsp;Madhusudhana Rao N,&nbsp;Basit Iqbal,&nbsp;Purnendu Ray","doi":"10.1016/j.physe.2025.116435","DOIUrl":"10.1016/j.physe.2025.116435","url":null,"abstract":"<div><div>Research into Diluted Magnetic Semiconductors (DMS) has experienced significant advancement over the past decade. This progress is largely attributable to the development of sophisticated synthesis techniques, which have enabled the fabrication of high-quality samples with well-characterized properties for experimental study. Consequently, DMS are widely regarded as a leading material platform for the development of spintronic devices. This study comprehensively investigates the first-principles study of SnS₂ and structural, morphological, chemical, optical, and magnetic properties of hydrothermally prepared pure and Cobalt-doped SnS₂ (1 %, 3 %, 5 %, 7 %) nanoparticles. X-ray diffraction analysis confirms the preservation of the hexagonal crystal phase post-doping. In contrast, Williamson-Hall (W-H) plot analysis indicates an increase in crystallite size from 32.9 nm to 66.8 nm with Co concentration. FESEM reveals a nanoflower-like morphology. X-ray photoelectron spectroscopy verifies the presence of Sn⁴⁺ and S²⁻ states and confirms the successful incorporation of Co dopants, which exhibit mixed Co²⁺/Co³⁺ oxidation states. Optical characterization demonstrates a reduction in reflectance and a narrowing of the optical band gap from 2.26 eV to 1.56 eV with doping. Density functional theory shows that the band gap of pure SnS₂ is direct. The Urbach energy, initially increasing up to 3 % Co doping, suggests a rise in structural disorder, followed by a subsequent decrease. A reduction in the refractive index from 4.62 to 3.10 indicates enhanced optical transmission, while a increase in optical and decrease in electrical conductivity is observed. The tunability of the emission wavelength across the visible spectrum, as observed in the photoluminescence (PL) spectra, is directly enabled by Co-doping. This controllability underscores the material's strong potential for application in advanced optoelectronic devices. Furthermore, the observed hysteresis loop confirms the emergence of ferromagnetic ordering upon cobalt doping. These findings collectively demonstrate that Cobalt-doped SnS₂ is a promising diluted magnetic semiconductor (DMS) material, whose tunable properties make it a strong candidate for application in spintronics and multifunctional optoelectronic devices.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"177 ","pages":"Article 116435"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737372","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":"Broadband perfect absorber based on graphene-silicon Mie heterojunctions for cancer cell detection","authors":"Qingbing Yang ,&nbsp;Lili Zeng ,&nbsp;Minghua Wang ,&nbsp;Bingwei Guo ,&nbsp;Yufan Deng ,&nbsp;Shuxin Xu ,&nbsp;Boxun Li","doi":"10.1016/j.physe.2025.116456","DOIUrl":"10.1016/j.physe.2025.116456","url":null,"abstract":"<div><div>In this paper, a composite architecture is pioneered, comprising a three-layer heterostructure of patterned graphene and silicon cylinder-embedded dielectric. To leverage strong Mie resonances triggered by embedded silicon pillars, an octagonal–cross–octagonal stacked graphene configuration is introduced. The key innovation is the demonstration of synergistic triple-mode coupling among Mie resonance, plasmonic mode, and Fabry–Pérot cavity resonance in the terahertz regime, which seamlessly fuses multiple discrete absorption peaks into a broadband spectrum. The absorber achieves an unprecedented absorption exceeding 96 % within 6.22–11.62 THz, setting a bandwidth record of 5.40 THz (fractional bandwidth of 60.5 %), with absorption over 98 % sustained across a 1.86 THz sub-band. Dynamic modulation of absorption characteristics is readily attainable by adjusting graphene's Fermi level and relaxation time. The absorption remains robust for incident angles up to 22.92°owing to its rotationally symmetric design, effectively eliminating angle dependence. Pushing the frontier further, this structure is innovatively harnessed for biomedical sensing, where the redshift of resonance peaks enables clear differentiation between healthy cells and breast cancer cells. Traditional methods primarily rely on monitoring the shifts of resonance peaks or dips, while this study, leveraging the field enhancement properties of the structure, further proposes a new sensitivity metric based on changes in absorption intensity for dual verification. It is this dual mechanism that ultimately achieves a high sensitivity of 4.29 THz/RIU and an intensity sensitivity of 55.89 %, opening up a new pathway for terahertz biosensing applications. This work transcends the longstanding trade-off between bandwidth and tunability in conventional terahertz absorbers, opening up a new pathway for terahertz biosensing applications.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"177 ","pages":"Article 116456"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884276","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":"Optically controlled high-performance terahertz modulator enabled by GeSe2/Si heterojunctions","authors":"Tong Lv ,&nbsp;Qifubo Geng ,&nbsp;Xunjun He ,&nbsp;Mingze Zhang ,&nbsp;Sergey Maksimenko","doi":"10.1016/j.physe.2025.116448","DOIUrl":"10.1016/j.physe.2025.116448","url":null,"abstract":"<div><div>In this study, we fabricated a broadband terahertz (THz) modulator based on an optically controlled GeSe₂/Si heterojunction via magnetron sputtering and vacuum selenization. The structural and morphological properties of the fabricated GeSe2 film were characterized using XRD, Raman, SEM, and AFM. Under 532 nm laser excitation, the device exhibited a modulation depth more seven times higher than that of bare silicon. At a pump density of 1500 mW/cm², effective modulation was achieved over a broad bandwidth of 0.2–1 THz, with a maximum modulation depth of ∼60 % at 1 THz. Systematic analysis revealed that the enhanced modulation performance originates from efficient separation and accumulation of photogenerated carriers at the heterojunction interface. Therefore, this study not only provides fundamental insights into the optoelectronic dynamics of GeSe₂-based heterostructures, but also supports their potential for application in advanced THz devices, including modulators, filters, and polarizers.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"177 ","pages":"Article 116448"},"PeriodicalIF":2.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787220","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":"Analytical modeling of electron mobility in non-degenerate and degenerate bulk n-Ge1-xSnx","authors":"Bratati Mukhopadhyay,&nbsp;P.K. Basu","doi":"10.1016/j.physe.2025.116388","DOIUrl":"10.1016/j.physe.2025.116388","url":null,"abstract":"<div><div>Direct bandgap Ge_1-xSn_x (x &gt; 0.08) alloys have emerged as highly promising materials for next-generation high-speed electronic, thermoelectric, and photonic devices, owing to their tunable band structure and compatibility with standard CMOS technology on silicon platforms. The transition from indirect to direct band gap for Sn concentration exceeding 8 % has made these alloys attractive for photonic applications such as mid-infrared lasers, modulators, and photodetectors, particularly in the 2–5 μm wavelength range. An earlier study predicted that the electron mobility in the non-degenerate Ge_1-xSn_x alloy would increase by 50 times for x ≥ 0.08 from the value in pure Ge (3900 cm²/V-sec) due to increased separation between Γ and L valleys and consequent reduction in intervalley scattering. In the present work, a realistic theoretical estimate is made of mobility of bulk Ge_1-xSn_x under both non-degenerate and degenerate condition for a wide range of Sn concentration (0 &lt; x &lt; 0.2) covering indirect and direct bandgap nature of the alloy. The theoretical values of mobility show excellent agreement with the experimental values reported for x = 0.02, and satisfactory agreement for x = 0.125. For the calculation of mobility, scattering by phonons (deformation potential acoustic, optical and intervalley), alloy-disorder, impurity as well as electron-electron scattering have been taken into consideration.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"175 ","pages":"Article 116388"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324746","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":"Klein tunneling and Fabry–Pérot resonances in twisted bilayer graphene","authors":"A. Bahlaoui ,&nbsp;Y. Zahidi","doi":"10.1016/j.physe.2025.116379","DOIUrl":"10.1016/j.physe.2025.116379","url":null,"abstract":"<div><div>The paper discusses the Klein tunneling and Fabry–Pérot resonances of charge carriers through a rectangular potential barrier in twisted bilayer graphene. Within the framework of the low-energy excitations, the transmission probability and the conductance are obtained depending on the parameters of the problem. Owing to the moiré-induced anisotropy of the Hamiltonian in twisted bilayer graphene, the propagation of charge carriers exhibits an anisotropic behavior in Klein tunneling and Fabry–Pérot resonances. Moreover, we show that the anisotropy of the charge carriers induces asymmetry and deflection in the Fabry–Pérot resonances and Klein tunneling, and they are extremely sensitive to the height of the potential applied. Additionally, we found that the conductance is strongly sensitive to the barrier height but weakly sensitive to the barrier width. Therefore, it is possible to control the maxima and minima of the conductance of charge carriers in twisted bilayer graphene. With our results, we gain an in-depth understanding of tunneling properties in twisted bilayer graphene, which may help in the development and design of novel electronic nanodevices based on anisotropic 2D materials.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"175 ","pages":"Article 116379"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159088","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":"Quantum Hall-like effect for neutral particles with magnetic dipole moments in a quantum dot","authors":"Carlos Magno O. Pereira,&nbsp;Edilberto O. Silva","doi":"10.1016/j.physe.2025.116381","DOIUrl":"10.1016/j.physe.2025.116381","url":null,"abstract":"<div><div>We predict a new class of quantum Hall phenomena in completely neutral systems, demonstrating that the interplay between radial electric fields and dipole moments induces exact <span><math><mrow><msup><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mi>h</mi></mrow></math></span> quantization without Landau levels or external magnetic fields. Contrary to conventional wisdom, our theory reveals that: (i) the singularity of line charges does not destroy topological protection, (ii) spin control of quantization emerges from boundary conditions alone, and (iii) the effect persists up to 25 K, surpassing typical neutral systems. These findings establish electric field engineering as a viable route to topological matter beyond magnetic paradigms.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"175 ","pages":"Article 116381"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220919","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 optoelectronic and hydrogen evolution reaction properties of decorated 2D materials (Ga2O3 monolayer, ZnO monolayer and borophene)","authors":"Rongzhi Wang ,&nbsp;Jin-Cheng Zheng","doi":"10.1016/j.physe.2025.116372","DOIUrl":"10.1016/j.physe.2025.116372","url":null,"abstract":"<div><div>Two-dimensional (2D) materials have received considerable attention for next-generation technological applications due to their unique physical properties. Herein, decorated monolayers (O-V-Ga₂O₃-m, Co doped ZnO-m and Fe cluster@Borophene) with high visible light absorption ability and hydrogen evolution reaction (HER) catalytic performance are reported. Strain and electric field could precisely tune the optical and HER properties of O-V-Ga₂O₃-m, Co doped ZnO-m and Fe cluster@Borophene. It is shown that the absorption peaks in the visible region red-shift with the increasement of strain or adding electric field. Both strain and electric field can modulate the absorption peaks of decorated monolayers in the visible zone and help to obtain optimal HER performance. These features advocate effective applications of O-V-Ga₂O₃-m, Co doped ZnO-m and Fe cluster@Borophene in optoelectronic devices and HER electrocatalysts.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"175 ","pages":"Article 116372"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047640","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":"Detecting topological phase transition in monolayer jacutingaite Pt2HgSe3 via thermal and magnetic properties","authors":"Tran Cong Phong ,&nbsp;Ta T. Tho ,&nbsp;Le T.T. Phuong","doi":"10.1016/j.physe.2025.116395","DOIUrl":"10.1016/j.physe.2025.116395","url":null,"abstract":"<div><div>We investigate the topological properties of monolayer jacutingaite Pt<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>HgSe<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> by analyzing its thermal and magnetic responses under static and dynamic electric fields. In doing so, we use the Kane–Mele model and the semiclassical Boltzmann approach. Through semiclassical calculations, we demonstrate how topological phase transitions induced by these fields are reflected in the material’s electronic heat capacity and Pauli spin susceptibility. We find that in the semimetallic phase, the low-temperature regime exhibits the highest magnitudes of these properties. In contrast, the responses are weaker and stronger for the band insulator and quantum Hall insulator phases, respectively, than the pristine quantum spin Hall insulator phase. This work offers a pathway for detecting topological features in the thermal and magnetic properties of materials.</div></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"175 ","pages":"Article 116395"},"PeriodicalIF":2.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363367","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}