- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tailoring Carrier Dynamics in Perovskite Solar Cells via Precise Di-mension and Architecture Control and Interfacial Positioning of Plasmonic Nanoparticles
摘要： Placing plasmonic nanoparticles (NPs) in close proximity to semiconductor nanostructures renders effective tuning of the optoelectronic properties of semiconductors through the localized surface plasmon resonance (LSPR)-induced enhancement of light absorption and/or promotion of carrier transport. Herein, we report on, for the first time, the scrutiny of carrier dynamics of perovskite solar cells (PSCs) via sandwiching monodisperse plasmonic/dielectric core/shell NPs with systematically varied dielectric shell thickness yet fixed plasmonic core diameter within electron transport layer (ETL). Specifically, a set of Au NPs with precisely controlled dimensions (i.e., fixed Au core diameter and tunable SiO2 shell thickness) and architectures (plain Au NPs and plasmonic/dielectric Au/SiO2 core/shell NPs) are first crafted by capitalizing on the star-like block copolymer nanoreactor strategy. Subsequently, these monodisperse NPs are sandwiched between the two consecutive TiO2 ETLs. Intriguingly, there exists a critical dielectric SiO2 shell thickness, below which hot electrons from Au core are readily injected to TiO2 (i.e., hot electron transfer (HET)); this promotes local electron mobility in TiO2 ETL, leading to improved charge transport and increased short-circuit current density (Jsc). It is also notable that the HET effect moves up the Fermi level of TiO2, resulting in an enhanced built-in potential and open-circuit voltage (Voc). Taken together, the PSCs constructed by employing a sandwich-like TiO2/Au NPs/TiO2 ETL exhibit both greatly enhanced Jsc and Voc, delivering champion PCEs of 18.81% and 19.42% in planar and mesostructured PSCs, respectively. As such, the judicious positioning of rationally designed monodisperse plasmonic NPs in ETL affords effective tailoring of carrier dynamics, thereby providing a unique platform for developing high-performance PSCs.
关键词： hot electron transfer,perovskite solar cells,plasmonic nanoparticles,carrier dynamics,localized surface plasmon resonance
更新于2025-09-23 15:19:57
-
Arbitrary control of the diffusion potential between a plasmonic metal and a semiconductor by an angstrom-thick interface dipole layer
摘要： Localized surface plasmon resonances (LSPRs) are gaining considerable attention due to the unique far-field and near-field optical properties and applications. Additionally, the Fermi energy, which is the chemical potential, of plasmonic nanoparticles is one of the key properties to control hot-electron and -hole transfer at the interface between plasmonic nanoparticles and a semiconductor. In this article, we tried to control the diffusion potential of the plasmonic system by manipulating the interface dipole. We fabricated solid-state photoelectric conversion devices in which gold nanoparticles (Au-NPs) are located between strontium titanate (SrTiO3) as an electron transfer material and nickel oxide (NiO) as a hole transport material. Lanthanum aluminate as an interface dipole layer was deposited on the atomic layer scale at the three-phase interface of Au-NPs, SrTiO3, and NiO, and the effect was investigated by photoelectric measurements. Importantly, the diffusion potential between the plasmonic metal and a semiconductor can be arbitrarily controlled by the averaged thickness and direction of the interface dipole layer. The insertion of an only one unit cell (uc) interface dipole layer, whose thickness was less than 0.5 nm, dramatically controlled the diffusion potential formed between the plasmonic nanoparticles and surrounding media. This is a new methodology to control the plasmonic potential without applying external stimuli, such as an applied potential or photoirradiation, and without changing the base materials. In particular, it is very beneficial for plasmonic devices in that the interface dipole has the ability not only to decrease but also to increase the open-circuit voltage on the order of several hundreds of millivolts.
关键词： interface dipole,Fermi energy,strontium titanate,nickel oxide,hole transfer,hot-electron,lanthanum aluminate,gold nanoparticles,photoelectric conversion,Localized surface plasmon resonances
更新于2025-09-23 15:19:57
-
Pump depletion and hot-electron generation in long-density-scale-length plasma with shock-ignition high-intensity laser
摘要： Two-dimensional particle-in-cell simulations for laser plasma interaction with laser intensity of 1016 W/cm2, plasma density range of 0.01–0.28nc, and scale length of 230–330 μm showed signi?cant pump depletion of the laser energy due to stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in the low-density region (ne = 0.01–0.2nc). The simulations identi?ed hot electrons generated by SRS in the low-density region with moderate energy and by two-plasmon-decay near ne = 0.25nc with higher energy. The overall hot electron temperature (46 keV) and conversion ef?ciency (3%) were consistent with the experiment’s measurements. The simulations also showed arti?cially reducing SBS would lead to stronger SRS and a softer hot-electron spectrum.
关键词： pump depletion,two-plasmon-decay,stimulated Raman scattering,stimulated Brillouin scattering,laser plasma interaction,hot-electron generation
更新于2025-09-23 15:19:57
-
Design, Simulation and Fabrication of Highly Sensitive Cooled Silicon Bolometers for Millimeter-Wave Detection
摘要： This paper reports our results on the electrothermal modeling of cryogenic silicon bolometers with pixel pitches of 500 and 1200 μm designed for cosmic microwave background polarimetric observation in 0.6 mm and 1.5 mm bands. These detectors should provide a high responsivity, typically around 1011 V/W, and a very low noise equivalent power (NEP) of 10?18 W/Hz1/2 between 50 and 100 mK. They are based on doped silicon thermometers, which exhibit a nonohmic behavior described by the “hot electron model” (HEM) at very low temperature under high bias currents. We compare this model to the experimental characterization of these thermometers at cryogenic temperatures to confirm that the HEM is governing their electrical characteristics and their sensitivity at very low temperature. Finally, this model is used to derive the simulated responsivity and NEP performances of the pixels under weak and moderate optical power illumination.
关键词： Cryogenic temperature,Hot electron model,Silicon bolometer
更新于2025-09-23 15:19:57
-
Anti-Stokes Emission from Hot Carriers in Gold Nanorods
摘要： The origin of light emission from plasmonic nanoparticles has been strongly debated lately. It is present as the background of surface enhanced Raman scattering, and, despite the low yield, has been used for novel sensing and imaging application because of its photostability. While the role of surface plasmons as an enhancing antenna is widely accepted, the main controversy regarding the mechanism of the emission is its assignment to either radiative recombination of hot carriers (photoluminescence) or electronic Raman scattering (inelastic light scattering). We have previously interpreted the Stokes shifted emission from gold nanorods as the Purcell effect enhanced radiative recombination of hot carriers. Here we specifically focused on the anti-Stokes emission from single gold nanorods of varying aspect ratios with excitation wavelengths below and above the inter-band transitions threshold while still employing continuous wave lasers. Analysis of the intensity ratios between Stokes and anti-Stokes emission yields temperatures that can only be interpreted as originating from the excited electron distribution and not a thermally equilibrated phonon population despite not using pulsed laser excitation. Consistent with this result as well as previous emission studies using ultrafast lasers, the power-dependence of the upconverted emission is nonlinear and gives the average number of participating photons as a function of emission wavelength. Our findings thus show that hot carriers and photoluminescence play a major role in the upconverted emission.
关键词： surface plasmon resonance,anti-Stokes photoluminescence,interband transition,intraband transition,hot electron temperature,gold nanoparticle
更新于2025-09-19 17:15:36
-
Enhancing the Output Performance of Triboelectric Nanogenerator via Grating‐Electrode‐Enabled Surface Plasmon Excitation
摘要： The surface charge density and the output impedance of triboelectric nanogenerators (TENGs) are two critical factors for TENGs to speed up their commercialization, so it is important to explore unique methods to reduce the output impedance and increase the surface charge density. Here, an approach is demonstrated to effectively boost the output performance of TENG while reducing the output impedance of TENGs by utilizing grating-electrode-enabled surface plasmon excitation. A sustainable and enhanced output performance of about 40 μA (short-circuit current) and 350 V (peak-to-peak voltage at a resistance of 10 MΩ) is produced via grating-coupled surface plasmon resonance on the TENG with the aluminum grating electrode in the line density of 600 lines mm?1, and it delivers a peak output power of 3.6 mW under a loading resistance of 1 MΩ, giving over 4.5-fold enhancement in output power and a 75% reduction in the output impedance. Finally a self-powered ultrasonic ranging system is utilized to verify the capability of the TENG in powering portable electrics.
关键词： optical grating,surface plasmon resonance,hot electron–hole pairs,triboelectric nanogenerators
更新于2025-09-19 17:13:59
-
Plasmonic hot electron transfer in anisotropic Pt–Au nanodisks boosts electrochemical reactions in the visible-NIR region
摘要： Plasmonic hot electron transfer in anisotropic Pt–Au nanodisks boosts electrochemical reactions in the visible-NIR region. Anisotropic plasmonic metals have attracted significant attention in enhancing the catalytic performance of catalysts due to their broad light-harnessing capabilities and active hot electrons; however, limited investigations have been dedicated towards improving their electrochemical reaction performance in the visible and near infrared (NIR) regions. Herein, anisotropic Pt-edged Au nanodisks (NDs) were synthesized by controlling the preferential loading of Pt and used as catalysts for plasmon-enhanced electrochemical methanol oxidation reactions (MORs) under visible-NIR light irradiation by, and the light-enhanced electric current over the Pt-edged Au NDs was found to be 3-fold higher than that under dark conditions. Wavelength-dependent electric current over the Pt-edged Au NDs for the MOR in the visible-NIR light region demonstrates that the light-induced enhancement of the electric current is due to surface plasmon resonance (SPR) of the Au NDs. Furthermore, plasmonic hot electron transfer was studied by the single-particle photoluminescence images and spectra of Au NDs and Pt–Au NDs, and the dipole surface plasmon resonance (DSPR) mode was proved to be the main channel for hot electron transfer. During the electrochemical reaction under visible-NIR light irradiation, a plasmonic hot electron is transferred to the electrode, and a 'hot hole' is left on the surface, boosting the MOR.
关键词： Pt–Au nanodisks,Plasmonic hot electron transfer,electrochemical reactions,visible-NIR region
更新于2025-09-16 10:30:52
-
Hot-electron dynamics in quantum dots manipulated by spin-exchange Auger interactions
摘要： The ability to effectively manipulate non-equilibrium ‘hot’ carriers could enable novel schemes for highly efficient energy harvesting and interconversion. In the case of semiconductor materials, realization of such hot-carrier schemes is complicated by extremely fast intraband cooling (picosecond to subpicosecond time scales) due to processes such as phonon emission. Here we show that using magnetically doped colloidal semiconductor quantum dots we can achieve extremely fast rates of spin-exchange processes that allow for ‘uphill’ energy transfer with an energy-gain rate that greatly exceeds the intraband cooling rate. This represents a dramatic departure from the usual situation where energy-dissipation via phonon emission outpaces energy gains due to standard Auger-type energy transfer at least by a factor of three. A highly favourable energy gain/loss rate ratio realized in magnetically doped quantum dots can enable effective schemes for capturing kinetic energy of hot, unrelaxed carriers via processes such as spin-exchange-mediated carrier multiplication and upconversion, hot-carrier extraction and electron photoemission.
关键词： quantum dots,spin-exchange Auger interactions,semiconductor materials,hot-electron dynamics,energy harvesting
更新于2025-09-16 10:30:52
-
Au/TiO2 nanotube array based multi-hierarchical architecture for highly efficient dye-sensitized solar cells
摘要： Control over balanced high light-harvesting and efficient charge transport is of crucial importance for photoelectrochemical applications but still remains great challenge. We develop here single-wall TiO2 nanotube array with in-situ deposited Au nanoparticles. Based on this Au–TiO2 hybrid, we further build a “cigar-like” Au/TiO2-nanotube-array/TiO2-nanoparticles multi-hierarchical architecture through a novel vacuum-assisted colloid-filling approach for dye-sensitized solar cell application. In this elaborate structure, Au nanoparticles welding on nanotube walls play dual roles of direct injecting hot electrons into TiO2 to elevate the conductivity of TiO2 film by about 4 times (under illumination) for fast electron transport, and introducing a plasmonic effect to improve light-harvesting as well. Meanwhile, the thick TiO2 nanoparticulate decoration provides the photoanode vast surface area for ~3.2 times the dye-loading amount of the pristine TiO2 nanotube array based electrode, which will further boost the light-harvesting remarkably. The resulting dye-sensitized solar cell yields an impressively high power conversion efficiency of 8.93%, which is 190.4% that of the pristine TiO2 nanotube array based device. The technology presented in this work provides also a promising prospect for the preparation of multi-hierarchical structures for a wide range of applications, such as photocatalysis and gas sensors.
关键词： Hot electron,Vacuum filling,Dye-sensitized solar cells,Hierarchical structure,Plasmon
更新于2025-09-12 10:27:22
-
Nanorectenna spectrally-selective plasmonic hot electron response to visible-light lasers
摘要： Active metasurfaces with novel visible and infrared (vis/IR) functionalities represent an exciting, growing area of research. Rectification of vis/IR frequencies would produce needed direct current (DC) with no inherent frequency limitation (e.g., no semiconducting bandgap). However, controlling the materials and functionality of (nano)rectennas for rectifying 100s of THz to the visible regime is a daunting challenge, because of the small features and simultaneously the need to scale up to large sizes in a scalable platform. An active metasurface of a planar array of nanoscale antennas on top of rectifying vertical diodes is a “nanorectenna array” or “microrectenna array” that rectifies very high frequencies in the infrared, or even higher frequencies up to the visible regime. We employ a novel strategy for forming optical nanorectenna arrays using scalable patterning of Au nanowires, demonstrate strong evidence for spectral-selective high-frequency rectification, characteristic of optical antennas. We discover a previously unreported out-of-equilibrium electron energy distribution, i.e. hot electrons arising from plasmonic resonance absorption in an optical antenna characterized by an effective temperature, and how this effect can significantly impact the observed rectification.
关键词： nanorectenna,spectrally-selective,hot electron,plasmonic,visible-light lasers
更新于2025-09-12 10:27:22