- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Investigation of valence plasmon excitations in GMZO thin film and their suitability for plasmon-enhanced buffer-less solar cells
摘要： The approach of eliminating buffer layer in conjunction with plasmon-enhanced transparent conduction oxide (TCO) layer is an attractive methodology to realize low-cost ultrathin buffer-less solar cells (SCs) by introducing plasmon-enhanced absorption and reduced fabrication steps. Here, we report a novel method to generate wide-band sputter-stimulated plasmonic feature in Ga-doped-MgZnO (GMZO) thin-films, which are observed due to the different metallic and metal-oxide nanoclusters formation. Through an extensive analysis of photoelectron spectroscopy, spectroscopic ellipsometry, and field-emission scanning electron microscope measurements the evaluation of plasmonic features and correlation of them with various nanoclusters inside GMZO thin-film is performed. Additionally, the suitability and expected performance of plasmon-enhanced GMZO thin-film based buffer-less SCs are probed through; 1) band-offset analysis at the plasmon enhanced-GMZO/CIGSe heterojunction; 2) simulation studies to analyze the effect of conduction band-offset (CBO) on the performance of the buffer-less SCs; 3) predicting the performance of the buffer-less SC using the parameters of GMZO thin-films with varying CBO, and 4) envisaging the concept of ultrathin buffer-less SC with calculated CBO and absorber layer thickness (300 nm) for ultrathin SCs. Moreover, at the experimentally calculated band-offset with ultrathin absorber layer thickness (300 nm), theoretically calculated buffer-less SC performance parameters estimated to be open-circuit voltage (Voc): 0.75 V, short-circuit current density (Jsc): 17.29 mA/cm2, fill-factor (FF): 80.5%, and efficiency (Eff): 10.46%.
关键词： Ultrathin solar cells,UPS,CIGSe,Plasmons
更新于2025-11-21 11:03:13
-
Investigation of valence electron excitation and plasmonic enhancement in sputter grown NMZO thin films: For energy harvesting applications
摘要： We report a novel approach of sputter-stimulated plasmonic generation in Na-doped MgZnO (NMZO) thin films. Sputtering of material during film growth by utilizing secondary direct-coupled ion-source present in dual-ion beam sputtering system leads to the generation of nanoclusters of its constituent elements due to different sputtering-out rates of various elements present in the films. The authentication of plasmonic generation in NMZO is conducted as follows a) identification of plasmonic signature in electron energy loss spectra obtained by ultraviolet photoelectron spectroscopy measurement, b) valence bulk, valence surface, and particle plasmon resonance energy calculations are performed, and each plasmon peak is indexed with corresponding plasmon energy peak of different nanoclusters, and c) spectroscopic ellipsometric measurement is deployed to verify plasmonic behavior by investigating different optical properties. Additionally, incorporation of the plasmonic feature along with alkali metals plays a crucial role in the improvement of the performance of solar cells. Therefore, plasmon enhanced NMZO as a backscattering layer in between CIGSe/back contact is probed to ascertain the additional benefits of 1) Na incorporation into the absorber layer as a result of the Na diffusion from the NMZO layer, and 2) improvement in the morphology of the CIGSe thin film with the incorporation of NMZO layer in between the back-contact and CIGSe. The diffusion of Na into the absorber layer is probed by deploying secondary ion mass spectroscopy measurements, and improvement in the morphology of CIGSe with the incorporation of NMZO layer between the back-contact/absorber is investigated using field-emission scanning electron microscope analysis.
关键词： UPS,NMZO,Ultrathin solar cells,Plasmons,Sputtered
更新于2025-11-21 11:03:13
-
The Sensing Applications in U-Shape Structure Based on Dual Transparency Windows
摘要： We have researched a U-shape structure that consists of three vertical cavities coupled with bus wave-guide. The theoretical results based on the coupled mode theory are consistent with simulation results. We demonstrate that the interaction among two bright and one dark modes lead to dual plasmon induced transparency. Meanwhile, it is found that the lateral displacement S plays an important role in the transmission property, and the transmission dip with different transmittance in various lateral displacement S has been explained theoretically. Moreover, the nano sensor has a sensitivity of 1225 nm shift per refractive index unit, and the ?gure of merit is up to 62.5. The proposed structure has the advantages of simple and compact structure, easy fabrication, and the ultra-compact structure holds great potential to the control of light in highly integrated optical circuits and nano sensor.
关键词： Surface plasmons,nano sensors,coupled mode theory
更新于2025-09-23 15:23:52
-
Edge-dependent reflection and inherited fine structure of higher-order plasmons in graphene nanoribbons
摘要： We investigate higher-order plasmons in graphene nanoribbons, and we present how electronic edge states and wave-function fine structure influence the graphene plasmons. Based on nearest-neighbor tight-binding calculations, we find that a standing-wave model based on nonlocal bulk plasmon dispersion is surprisingly accurate for armchair ribbons of widths even down to a few nanometers, and we determine the corresponding phase shift upon edge reflection and an effective ribbon width. Wider zigzag ribbons exhibit a similar phase shift, whereas the standing-wave model describes few-nanometer zigzag ribbons less satisfactorily, to a large extent because of their edge states. We directly confirm that also the larger broadening of plasmons for zigzag ribbons is due to their edge states. Furthermore, we report a prominent fine structure in the induced charges of the ribbon plasmons, which for armchair ribbons follows the electronic wave-function oscillations induced by intervalley coupling. Interestingly, the wave-function fine structure is also found in our analogous density-functional theory calculations, and both these and tight-binding numerical calculations are explained quite well with analytical Dirac theory for graphene ribbons.
关键词： plasmons,edge states,tight-binding,density-functional theory,Dirac theory,graphene nanoribbons
更新于2025-09-23 15:23:52
-
Asymptotic approximations for the plasmon resonances of nearly touching spheres
摘要： Excitation of surface-plasmon resonances of closely spaced nanometallic structures is a key technique used in nanoplasmonics to control light on subwavelength scales and generate highly confined electric-field hotspots. In this paper, we develop asymptotic approximations in the near-contact limit for the entire set of surface-plasmon modes associated with the prototypical sphere dimer geometry. Starting from the quasi-static plasmonic eigenvalue problem, we employ the method of matched asymptotic expansions between a gap region, where the boundaries are approximately paraboloidal, pole regions within the spheres and close to the gap, and a particle-scale region where the spheres appear to touch at leading order. For those modes that are strongly localised to the gap, relating the gap and pole regions gives a set of effective eigenvalue problems formulated over a half space representing one of the poles. We solve these problems using integral transforms, finding asymptotic approximations, singular in the dimensionless gap width, for the eigenvalues and eigenfunctions. In the special case of modes that are both axisymmetric and odd about the plane bisecting the gap, where matching with the outer region introduces a logarithmic dependence upon the dimensionless gap width, our analysis follows Schnitzer [Singular perturbations approach to localized surface-plasmon resonance: nearly touching metal nanospheres. Phys. Rev. B 92(23), 235428 (2015)]. We also analyse the so-called anomalous family of even modes, characterised by field distributions excluded from the gap. We demonstrate excellent agreement between our asymptotic formulae and exact calculations.
关键词： asymptotic analysis,eigenvalue problems,Surface plasmons
更新于2025-09-23 15:22:29
-
Photothermal-Assisted Optical Stretching of Gold Nanoparticles
摘要： The synergy of photothermal energy and optical forces generated by tightly focused laser beams can be used to transform the shape of gold nanoparticles. Here, the combination of these two effects is demonstrated to be an effective way of elongating gold nanoparticles (Au NPs), massively tuning their plasmonic properties. The photothermal effect of the laser increases the temperature of Au NPs above the melting point, and optical forces deform the molten Au NPs. As a result, the shape of Au NPs transforms from nanospheres into nanorods or dimers, depending on the power and time of irradiation as well as the surface energy of the substrate. This process is reversible by using high laser power to transform nanorods back to nanospheres due to capillary dewetting. Such light-induced transformations of nanostructures not only provide a facile way to tune plasmon resonances but also shed light on how the synergistic effect of photothermal energy and optical forces works on plasmonic nanoparticles.
关键词： rods,films,dimers,optical forces,plasmons
更新于2025-09-23 15:21:21
-
Performance study of surface plasmon resonance and lossy mode resonance based fiber optic sensors utilizing silver and indium oxide layers: An experimental investigation
摘要： This study presents here the experimental investigations on a surface plasmon resonance (SPR)/lossy mode resonance (LMR) based fiber optic sensors coated with silver and indium oxide layers. Different sensing probes have been fabricated by coating (i) a single layer of indium oxide, (ii) a single layer of silver and (iii) a double layer of indium oxide and silver (with different thicknesses) symmetrically onto to the bare core of silica fiber. The sensitivity of these fiber optic sensing probes towards surrounding region refractive index variations are determined using different concentrations of sucrose solutions. It was found that sensor probe fabricated with coating of 100 nm thickness of indium oxide was two times more sensitive than the conventionally used fiber optic sensing probe coated with only silver layer. The sensitivity of a double layer coated fiber optic sensor with various thicknesses of indium oxide and silver layers is in between the two extremes of the sensitivities. This study will find suitable applications in the field of chemical and biochemical sensing. The drawbacks of silver coatings and the advantages of LMR supporting indium oxide have also been discussed.
关键词： Surface plasmons,Sensitivity,Lossy mode resonances,Thin films,Fiber optic sensors,Detection accuracy,Indium oxide
更新于2025-09-23 15:21:21
-
Broadband light harvesting for highly efficient hot-electron application based on conformal metallic nanorod arrays
摘要： The utilization of nonradiative decay of surface plasmons (SPs) in the form of hot electrons in metallic nanostructures has a great potential for applications in photovoltaics, photocatalysis, photodetection, and surface imaging. Unfortunately, the metallic nanostructures usually support only narrowband plasmon resonances; moreover, the hot-electron thermalization loss during the transport to Schottky interface and the confined momentum space for hot-electron injection into semiconductor together result in an inefficient internal quantum process. In this study, we propose and experimentally demonstrate a broadband super absorber based on the metallic nanorod arrays (NRs). Optically, the average absorption across the entire visible band is up to 0.8, which is over 16-fold enhancement of the planar reference. Electrically, the hot electrons are controlled to be preferentially generated near Schottky interface within the mean free path, relieving the severe hot-electron thermalization loss. Moreover, the three-dimensional Schottky junction provides much increased hot-electron momentum space for injection at the vertical surface. These optical and electrical benefits lead to over 30-fold enhancement in the IPCE (incident photon-to-electron conversion efficiency) relative to the reference. The IPCE can be up to 10.9% at Eph = 3.1 eV, which is close to the limit of the thick-film single-barrier hot-electron devices. The conformal NRs system provides a promising strategy to simultaneously improve the hot-electron generation, transport and collection efficiencies and could be an outstanding candidate for efficient hot-electron optoelectronic and photocatalysis systems.
关键词： hot electron,surface plasmons,nanorod arrays,broadband absorber
更新于2025-09-23 15:21:21
-
Broadly Tunable Plasmons in Doped Oxide Nanoparticles for Ultrafast and Broadband Mid-Infrared All-Optical Switching
摘要： Plasmons in conducting nanostructures offer the means to efficiently manipulate light at the nanoscale with subpicosecond speed in an all-optical operation fashion, thus allowing for constructing high performance all-optical signal-processing devices. Here, by exploiting the ultrafast nonlinear optical properties of broadly tunable mid-infrared (MIR) plasmons in solution-processed, degenerately doped oxide nanoparticles, we demonstrate ultrafast all-optical switching in the MIR region, which features with subpicosecond response speed (with recovery time constant of ?400 fs) as well as ultrabroadband response spectral range (covering 3.0-5.0 μm). Furthermore, with the degenerately doped nanoparticles as Q-switch, pulsed fiber lasers covering 2.0-3.5 μm were constructed, of which a watt-level fiber laser at 3.0 μm band show superior overall performance among ever-reported passively Q-switched fiber lasers at the same band. Notably, the degenerately doped nanoparticles show great potential to work in the spectral range over 3.0 μm that is beyond the accessibility of commercially available but expensive semiconducting saturable absorber mirror (SESAM). Our work demonstrates a versatile while cost-effective material solution to ultrafast photonics in the technologically important MIR region.
关键词： tunable plasmons,ultrafast photonics,all-optical switching,doped oxide nanoparticles,mid-infrared
更新于2025-09-23 15:21:21
-
Highly tunable multiple narrow emissions of dyed dielectric-metal core-shell resonators: towards efficient fluorescent labels
摘要： We report a potential efficient fluorescent label based on the dyed dielectric-metal core-shell resonators. By utilizing the near-field coupling between the dyes and the multipolar sharp cavity plasmon resonances, the dyed dielectric-metal core-shell resonators with diameter of 1.02 μm are demonstrated to be capable of supporting multiple spontaneous emission peaks with the linewidths as narrow as ~ 10 nm in visible range, and these reshaped fluorescent emissions are insensitive to the surrounding dielectric environment. Furthermore, these multiple narrow emission peaks show a precise tunability on the spectrum by simply separating a nanometric dielectric layer between the dielectric core and the metallic shell, which may provide an attractive spectral multiplexing strategy in the fields of cell biology and medical sciences.
关键词： spectral multiplexing,cavity plasmons,fluorescent label,dyed dielectric-metal core-shell resonators,quality factor
更新于2025-09-23 15:21:21