{"title":"Observation of voltage dependent negative differential resistance (NDR) in SnS2-GO nanocomposites","authors":"Lohnye Tangjang , Anubhab Parashar Gogoi , Hirendra Das , Sagar Bhattarai , P.K. Kalita","doi":"10.1016/j.physe.2024.116102","DOIUrl":"10.1016/j.physe.2024.116102","url":null,"abstract":"<div><p>This study investigates the structural, optical, and electrical properties of tin disulfide (SnS<sub>2</sub>) and SnS<sub>2</sub>-graphene oxide (GO) nanosheets synthesized via chemical bath deposition method (CBD). Structural characterization confirms the formation of hexagonal crystal phases with nanosheet morphology. It shows a well distribution of nanosheet average square sizes of 10 nm for SnS<sub>2</sub> and 6 nm for SnS<sub>2</sub>-GO. Optical analysis shows blue shifts in absorption edges compared to bulk SnS<sub>2</sub>, attributed to quantum confinement effects. Photoluminescence emission peaks exhibit different energy levels in SnS<sub>2</sub>-GO originated to native defects. The composites show a sharp reduced of PL intensity due to enhanced charge carrier separation. Electrical measurements on SnS<sub>2</sub>-GO thin films demonstrate negative differential resistance (NDR) behavior in both planar and sandwich contact configurations, suggesting electron injection/extraction mechanisms. The NDR phenomenon exhibits a dependence on voltage scan rate, indicating the involvement of electronic and ionic elements in charge transport mechanisms. Overall, this study provides insights into the NDR properties of SnS<sub>2</sub>-GO nanocomposite, laying the groundwork for their potential applications in optoelectronics and nanoelectronics.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116102"},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229634","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":"Reconfigurable spin-wave properties in two-dimensional magnonic crystals formed of diamond and triangular shaped nanomagnets","authors":"Swapnil Barman , Rajib Kumar Mitra","doi":"10.1016/j.physe.2024.116104","DOIUrl":"10.1016/j.physe.2024.116104","url":null,"abstract":"<div><p>Two-dimensional ferromagnetic nanodot structures exhibit intriguing magnetization dynamics and hold promise for future magnonic devices. In this study, we present a comparative experimental investigation into the reconfigurable magnetization dynamics of non-ellipsoidal diamond and triangular-shaped nanodot structures, employing broadband ferromagnetic resonance spectroscopy. Our findings reveal substantial variations in the spin wave (SW) spectra of these structures under different bias field strengths (<em>H</em>) and angles (<em>φ</em>). Notably, the diamond nanodot structure exhibits a variation from nearly symmetric W-shaped dispersion to a skewed dispersion and subsequent transition to a discontinuous dispersion with subtle variation in bias field angle. On the other hand, in the triangular nanodot array a SW mode anti-crossing appears at <em>φ</em> = 15° which is starkly modified with the increase in <em>φ</em> to 30°. By analyzing the static magnetic configurations, we unveil the nature of the SW spectra in these two shapes. We reinforce our observations with simulated spatial power and phase maps. This study underscores the critical impact of dot shape and inversion symmetry on SW dynamical response, highlighting the significance of selecting appropriate structures and bias field strength and orientation for required functionalities. The remarkable tunability demonstrated by the magnonic crystals underscores their potential suitability for future magnonic devices.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116104"},"PeriodicalIF":2.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142265511","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}
Hui Tu , Yuxiong Xue , Rongxing Cao , Yang Liu , Shu Zheng , Hongxia Li , Yuting Guo , Haiyi Sun , Dan Han
{"title":"Unveiling the impact of four-phonon scattering on thermal transport properties of the bulk β-Ga2O3 and monolayer Ga2O3","authors":"Hui Tu , Yuxiong Xue , Rongxing Cao , Yang Liu , Shu Zheng , Hongxia Li , Yuting Guo , Haiyi Sun , Dan Han","doi":"10.1016/j.physe.2024.116099","DOIUrl":"10.1016/j.physe.2024.116099","url":null,"abstract":"<div><p>In recent years, the role of four-phonon (4ph) scattering in thermal transport properties has been gradually revealed. However, the underlying scattering mechanisms of the bulk <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> and monolayer Ga<sub>2</sub>O<sub>3</sub> remain unclear. Hence, we evaluate the effect of 4ph scattering on the thermal transport properties of the bulk <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> and monolayer Ga<sub>2</sub>O<sub>3</sub> by utilizing first-principles calculations. It has been observed that the Young's modulus and lattice thermal conductivity (<em>κ</em>) of the bulk <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> are anisotropic, while the values of the monolayer Ga<sub>2</sub>O<sub>3</sub> are isotropic. The <em>κ</em> of the bulk <em>β</em>-Ga<sub>2</sub>O<sub>3</sub> along the three directions ([100], [010], and [001]) and monolayer Ga<sub>2</sub>O<sub>3</sub> after adding 4ph scattering are decreased by 9.23%, 11.52%, 13.89%, and 29.24% at 300 K, respectively. Moreover, the effect of four-phonon scattering is more pronounced at the high temperature. Afterwards, based on the phonon behaviors, we can prove that the addition of 4ph scattering can increase the phonon scattering rate, decrease the phonon mean free path, and increase the phase space, which results in lower thermal conductivity. The findings can contribute to a better understanding of high-order phonon scattering mechanisms of the Ga<sub>2</sub>O<sub>3</sub> materials.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116099"},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229632","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}
Qiyi Zhao , Ze Xue , Yani Ren , Kai Jiang , Xiuqin Wei , Huiran Yang , Jiming Zheng , Lu Li
{"title":"In-plane anisotropic dispersion property and second-harmonic generation of violet phosphorus with two-dimensional nano-interlocking structure","authors":"Qiyi Zhao , Ze Xue , Yani Ren , Kai Jiang , Xiuqin Wei , Huiran Yang , Jiming Zheng , Lu Li","doi":"10.1016/j.physe.2024.116100","DOIUrl":"10.1016/j.physe.2024.116100","url":null,"abstract":"<div><p>The unique one-dimensional chain structure of violet phosphorus provides an ideal platform for the study of second-order nonlinear optical properties. This also offers more possibilities for the further development of novel two-dimensional layered nanomaterials in the frequency domain. The research suggest that the highest occupied molecular orbital of monolayer phosphorene is characterized by a small effective mass and high hole mobility, while the lowest unoccupied molecular orbital exhibits opposite properties. This may be attributed to increased lattice scattering or electron-electron interactions in the conduction band. Monolayer violet phosphorus exhibits strong absorption capabilities in the near-ultraviolet light range, which can be utilized in UV spectroscopy technology for detecting harmful substances in water and air. Besides, its second harmonic generation response is also very strong within the visible light spectrum, and this response significantly varies with changes in angle. This provides theoretical guidance for optimizing the different stacking directions and heterojunction structures of violet phosphorus, more importantly, the sensitivity and directional selectivity of sensors can be improved. The work not only deepens the understanding of the electro-optical performance of violet phosphorus materials but also lays a theoretical foundation and guidance for the design and application of devices based on violet phosphorus.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116100"},"PeriodicalIF":2.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240795","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":"Local electronic interaction effects on electronic properties of tetragonal Germanene under bias voltage","authors":"H. Rezania , M. Abdi , B. Astinchap","doi":"10.1016/j.physe.2024.116098","DOIUrl":"10.1016/j.physe.2024.116098","url":null,"abstract":"<div><p>We study the effects of a transverse magnetic field and bias voltage on the electronic properties of buckled tetragonal Germanene in the context of Hubbard model with ferromagnetic ordering. In particular, the behavior of density of states and temperature dependence of specific heat, thermoelectric properties and magnetic susceptibility have been investigated. Mean field approximation has been employed in order to obtain the effects of local coulomb interaction on the band structure of the system. Our results show the band gap in the density of states decreases with increase of bias voltage. Also the low temperature dependence of specific heat of tetragonal Germanene is found to be exponentially increasing behavior with temperature for all magnetic field and local coulomb interaction strength values. Seebeck coefficient shows an increasing behavior in terms of temperature with positive sign for all values of interaction strength. However Seebeck coefficient gets both positive and negative signs due to variation of transverse magnetic field strength in the absence of coulomb interaction and bias voltage.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116098"},"PeriodicalIF":2.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149068","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}
M.A. Toloza Sandoval, A.L. Araújo, F. Crasto de Lima, A. Fazzio
{"title":"Transport fingerprints of helical edge states in Sierpiński tapestries","authors":"M.A. Toloza Sandoval, A.L. Araújo, F. Crasto de Lima, A. Fazzio","doi":"10.1016/j.physe.2024.116097","DOIUrl":"10.1016/j.physe.2024.116097","url":null,"abstract":"<div><p>Recently, synthesis and experimental research of fractalized materials has evolved in a paradigmatic crossroad with topological states of matter. Here, we present a theoretical investigation of the helical edge transport in Sierpiński carpets (SCs), combining the Bernevig–Hughes–Zhang model with the Landauer transport framework. By starting from a pristine two-dimensional topological insulator, the results reveal vanishing and reentrant resonant transport modes enabled for increased SC fractal generation. We observe that fractal with superior hierarchy inherits characteristics due to self-similarity and present conductance patterns resembling a miniband transport picture with fractal fingerprints. Real-space mapping of emerging resonant and antiresonant states provides an unprecedented view of helical-edge currents encoded in these intricate geometries and their multiple edges, underscoring the significance and consistency of our findings.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116097"},"PeriodicalIF":2.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173481","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":"Shot noise and tunneling magnetoresistance in silicene-based ferromagnet/antiferromagnet/ferromagnet/p-wave superconductor junctions","authors":"Yanya Xu , Hongmei Zhang , De Liu","doi":"10.1016/j.physe.2024.116094","DOIUrl":"10.1016/j.physe.2024.116094","url":null,"abstract":"<div><p>We investigate the transport properties in silicene-based ferromagnet/antiferromagnet/ferromagnet/p-wave superconductor junctions within the Blonder–Tinkham–Klapwijk formalism by solving the Dirac–Bogoliubov-de Gennes equation. The results show that the conductance and the shot noise strongly depend on the p-wave superconducting pair potentials and the magnetic configurations of the ferromagnetic regions. The simultaneous diminution of the conductance and enhancement of the shot noise can be achieved with the increase of the antiferromagnetic exchange field strength. The conductance and the shot noise can be effectively modulated by the external electric field and the ferromagnetic exchange field strength, and the corresponding switch effects are also achieved. The tunneling magnetoresistance (TMR) outside the subgap energy interval is always larger than the one obtained in the subgap energy interval. When the antiferromagnetic exchange field strength is large enough, a larger TMR can be obtained by tuning the external electric field.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116094"},"PeriodicalIF":2.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149067","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":"Nernst effect of the dice lattice in a strong magnetic field","authors":"Han-Lin Liu, J. Wang","doi":"10.1016/j.physe.2024.116096","DOIUrl":"10.1016/j.physe.2024.116096","url":null,"abstract":"<div><p>The dice lattice bears a similar honeycomb lattice structure to graphene but with a non-dispersive flat band intersecting the Dirac bands at the band center. In this work, we investigate Nernst effect of the dice lattice in a strong magnetic field, focusing on the role of the flat band. By using the Chebyshev polynomial Green’s function method, we show that no Nernst effect (<span><math><mrow><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub><mo>=</mo><mn>0</mn></mrow></math></span>) is around the Dirac point in the clean limit contrary to the graphene case because of the existence of a zero Hall conductivity platform. However, an unconventional negative <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub></math></span> of the double-peak structure emerges instead when the flat band is broadened by disorder and temperature. In addition, when a mass term of Dirac electrons is introduced in the system to open an energy gap, a negative single peak of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msub></math></span> appears at the Dirac point and this is due to the derivative quantum Hall effect of non-Dirac electrons in the flat band appearing in the energy gap.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116096"},"PeriodicalIF":2.9,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149144","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 on the interface electronic structure, strain modulation and transport properties of composite heterojunction of 2D semimetal TiS2 and MX2 (M=Mo, W, Cr, Zr, Hf; X=S, Se, Te) semiconductor","authors":"Quan Ru Liu , Ming Zhuo Zhao , Ying Xu","doi":"10.1016/j.physe.2024.116092","DOIUrl":"10.1016/j.physe.2024.116092","url":null,"abstract":"<div><p>Ohmic contacts play a crucial role in realizing high-performance electronic devices based on two-dimensional materials. The contact between semimetals and semiconductors can mitigate the formation of metal-induced gap states (MIGS), thereby reducing the SBH, enhancing the efficiency of high charge injection, and facilitating the establishment of ohmic contacts. This study involves a systematic exploration of the contact characteristics between the two-dimensional semimetal TiS<sub>2</sub> and semiconductor MX<sub>2</sub> (M = Mo, W, Cr, Zr, Hf; X = S, Se, Te) through first-principles calculations. It is found that the TiS<sub>2</sub>/MoSe<sub>2</sub> and TiS<sub>2</sub>/WSe<sub>2</sub> heterojunction achieve ohmic contact. Investigations into their transport properties reveal that significant currents can be observed at relatively low voltages, indicating excellent transport performance of these heterojunctions. The TiS<sub>2</sub>/CrSe<sub>2</sub> and TiS<sub>2</sub>/HfSe<sub>2</sub> contact heterojunctions also show low Schottky barrier height (SBH), with the barrier height being adjustable under strain. The SBH of TiS<sub>2</sub>/CrSe<sub>2</sub> and TiS<sub>2</sub>/HfSe<sub>2</sub> heterojunctions are very close to zero under stresses of 4 % and −4%, respectively. This also implies that our research can offer valuable guidance for the development of adjustable Schottky nano-devices and high-performance optoelectronic devices.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116092"},"PeriodicalIF":2.9,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121759","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}
Shah Ihsan , Syed Zulfiqar , Shaukat Ali Khattak , Hasan B. Albargi , Arshad Khan , Gul Rooh , Tahirzeb Khan , Gulzar Khan , Irfan Ullah
{"title":"The effect of solvent on the structural, morphological, optical and dielectric properties of SnO2 nanostructures","authors":"Shah Ihsan , Syed Zulfiqar , Shaukat Ali Khattak , Hasan B. Albargi , Arshad Khan , Gul Rooh , Tahirzeb Khan , Gulzar Khan , Irfan Ullah","doi":"10.1016/j.physe.2024.116095","DOIUrl":"10.1016/j.physe.2024.116095","url":null,"abstract":"<div><p>We investigate the effect of solvent, i.e., ethanol and deionized (DI) water, on the structural, optical, and dielectric characteristics of SnO<sub>2</sub> nanostructures, synthesized via the hydrothermal method. Utilizing X-ray diffraction (XRD), we find the rutile phase for both nanostructures with average crystallite sizes of 12.53 nm and 6.62 nm for the samples synthesized using ethanol and DI water as solvents, respectively. The energy-dispersive X-ray spectroscopy (EDX) confirms the presence of Sn and O elements in both samples. Scanning electron microscopy (SEM) reveals that the samples prepared using ethanol and DI water exhibit nanorods and nanoflowers structures, respectively. The calculated band gap for SnO<sub>2</sub> based on ethanol and DI water solvents is found to be 3.54 eV and 3.45 eV, respectively. The SnO<sub>2</sub> nanostructure prepared by ethanol solvent demonstrates a higher dielectric constant which is attributed to higher defect density and more grain boundaries in it than in the sample synthesized using DI water. At low frequencies, the high tan<strong><em>δ</em></strong> values in the case of both nanostructures are explained based on space-charge polarization (SPC). The SnO<sub>2</sub> prepared by DI water exhibits higher tangent loss than the one synthesized using ethanol because of its significant surface area. The significant amount of conducting grains in the SnO<sub>2</sub> nanostructure while using ethanol solvent makes it a better conductive. Furthermore, the dielectric constant increases with increasing temperature which suggests considerable changes in the polarization behavior, while the tangent loss and conductivity demonstrate dependency on the temperature, indicating the promise of the nanostructures for electrical applications.</p></div>","PeriodicalId":20181,"journal":{"name":"Physica E-low-dimensional Systems & Nanostructures","volume":"165 ","pages":"Article 116095"},"PeriodicalIF":2.9,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142128933","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}