Antidot lattices, defined on a two-dimensional electron gas at semiconductor heterostructure, are well-studied class of man-made structures with intriguing physical properties. We point out that closely related system, graphene sheets regularly spaced holes ("antidots"), should display similar phenomenology, but within much more favorable energy scale, consequence the Dirac fermion nature states around Fermi level. Further, by leaving some one can create defect states, or pairs coupled which...

Excitation of localized and delocalized surface plasmon resonances can be used for turning excellent reflectors visible light, such as gold silver, into efficient absorbers, whose wavelength, polarization or angular bandwidths are however necessarily limited owing to the resonant nature excitations involved. Nonresonant absorption has so far been achieved by using combined nano- micro-structural modifications with composite materials involving metal nanoparticles embedded in dielectric...

A capacity increase is often observed in the early stage of Li-ion battery cycling. This study explores phenomena involved from full cell, electrodes, and materials perspective through a combination non-destructive diagnostic methods cell post-mortem analysis coin cell. The results show an 1% initial for aged at 100% depth discharge (DOD) 45 °C. Furthermore, large DODs or high temperatures accelerate increase. From incremental differential voltage (IC-DV) analysis, we concluded that...

Abstract Broadband absorbers, with the simultaneous advantages of thermal stability, insensitivity to light polarization and angle, robustness against harsh environmental conditions, large area fabrication by scalable methods, are essential elements in (solar) thermophotovoltaics. Compared noble metal multilayered broadband high‐temperature refractory metal‐based nanostructures low‐Q resonators reported less. In this work, 3D titanium nitride (TiN) nanopillars investigated for ultrabroadband...

Efficient broadband absorption of visible and near-infrared light by low quality-factor metal-insulator-metal (MIM) resonators using refractory materials is reported.Omnidirectional incident for broad angles incidence polarization insensitivity are observed the fabricated MIM resonator.Excellent thermal stability absorber demonstrated at high operating temperatures (800 °C).The experimental spectra show good agreement with simulations.The resonator 12 nm top tungsten 100 alumina spacer film...

Understanding the aging mechanism for lithium-ion batteries (LiBs) is crucial optimizing battery operation in real-life applications. This article gives a systematic description of LiBs electric vehicle (EV) First, characteristics common EVs and chemistries used these applications are described. The then classified into three modes: charging, standby, driving, which subsequently Finally, behavior actual driving modes reviewed, influence different working conditions considered. degradation...

Abstract Titanium nitride (TiN) has emerged as one of the most promising refractory materials for plasmonic and photonic applications at high temperatures due to its prominent optical properties along with mechanical thermal stability. From a temperature standpoint, TiN is substitution Au Ag in visible near‐infrared wavelength range, potential including thermophotovoltaics, thermoplasmonics, hot‐electron reflective coatings. However, stability films strongly depend on growth conditions, such...

Electrochemical impedance spectroscopy (EIS) is an effective technique for Lithium-ion battery state of health diagnosis, and the spectrum prediction by charging curve expected to enable testing during vehicle operation. However, mechanistic relationship between curves remains unclear, which hinders development as well optimization EIS-based techniques. In this paper, we predicted voltage optimized input based on electrochemical analysis machine learning. The internal relationships curve,...

Fast charging is considered a promising protocol for raising the efficiency of electric vehicles. However, high currents applied to Lithium-ion (Li-ion) batteries inevitably accelerate degradation and shorten their lifetime. This work designs multi-step fast-charging method extend lifetime LiNi0.5Co0.2Mn0.3O2 (NMC)/graphite Li-ion based on studies half cells investigates aging mechanisms different methods. The has been studied from both full cell behaviour materials perspectives through...

Abstract The key to advancing lithium‐ion battery (LIB) technology, particularly with respect the optimization of cycling protocols, is obtain comprehensive and in‐depth understanding dynamic electrochemical processes during operation. This work shows that pulse current (PC) charging substantially enhances cycle stability commercial LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532)/graphite LIBs. Electrochemical diagnosis unveils pulsed effectively mitigates rise impedance minimizes loss electrode...

Undoped graphene is semimetallic and thus not suitable for many electronic optoelectronic applications requiring gapped semiconductor materials. However, a periodic array of holes (antidot lattice) renders semiconducting with controllable band gap. Using atomistic modeling, we demonstrate that this artificial nanomaterial dipole-allowed direct-gap very pronounced optical-absorption edge. Hence, optical infrared spectroscopy should be an ideal probe the structure. To address realistic...

A degradation model investigating the electro-thermo-mechanical fatigue, experienced by insulated gate bipolar transistors modules, is presented. To illustrate concept, a specific case of power modules subjected to active cycling which induce failure through bond wire lift-off considered. Bond believed be due thermally induced stress arising from mismatch in coefficients thermal expansion between wires and given substrate. Overall, theoretical evaluation based on determining...

Constant current charging and discharging is widely used nowadays for commercial lithium (Li) ion batteries (LIBs) in applications of portable electronic devices electric vehicles.

Surface-enhanced Raman spectroscopy (SERS) detection of analyte molecules at ultra-low concentrations requires highly-efficient plasmonic nanostructures enabling a high hot-spot density. However, facile and cost-effective strategy toward large-area fabrication efficient with significant electromagnetic field enhancement remains great challenge. Further, SERS faces reliability issues the molecular fingerprint concentrations. This work shows one-step rapid technique utilizing glancing angle...

Calculations of the optical properties solids require knowledge momentum matrix elements. Within tight-binding method, these are not readily available since wave functions expanded in an unknown basis. A popular solution to this problem is based on taking k-space gradient Hamiltonian. This technique was previously claimed be exact, but fact only approximate intra-atomic contributions emitted. We highlight reason for misconception. By comparison exact results from a simple model it...

Graphene can be rendered semiconducting via energy gaps introduced in a variety of ways, e.g., coupling to substrates, electrical biasing, or nanostructuring. To describe and compare different realizations gapped graphene we propose simple two-band model which ``mass'' term is responsible for the gap. The optical conductivity predicted this obtained as closed-form expression. In addition, analytical estimates binding excitons are derived impact on response analyzed.

We measure the second harmonic (SH) response of ${\mathrm{MoS}}_{2}$ in a broad fundamental photon energy range between 0.85 and 1.7 eV, present continuous SH spectrum capturing signatures both $A$ $B$ excitons addition to intense $C$ resonance. Moreover, we interpret our results terms an exciton simulation properties multilayered samples, represented by study trilayer ${\mathrm{MoS}}_{2}$. The good agreement theory experiments allows us establish connection measured underlying electronic...

High-temperature stable emitters with spectral selective functionality are an absolute condition for efficient conversion of thermal radiation into electricity using thermophotovoltaic (TPV) systems. Usually, made up multilayered materials or geometrical structures resulting from complex fabrication processes. Here, we report a spectrally emitter based on single metal layer coating molybdenum (Mo) over 3D dielectric pillar geometry. Mo nanopillars fabricated large-area and cost-effective...

The long-term operation of refractory-metal-based metamaterials is crucial for applications such as thermophotovoltaics. based on refractory metals like W, Mo, Ta, Nb, and Re fail primarily by oxidation. Here, the use noble metal Ir proposed, which stable to oxidation has optical properties comparable gold. thermal endurance in a 3-layer-system, consisting HfO2 /Ir/HfO2 , performing annealing experiments up 1240 °C pressure range from 2 × 10-6 mbar 1 bar, demonstrated. layer shows no vacuum...

Domain walls in periodically poled ferroelectric KTiOPO4 and LiNbO3 crystals are observed by making use of second-harmonic (SH) generation enhancement the transition regions between neighboring domains. SH images domain obtained with various samples for different polarization configurations presented. The is found especially pronounced radiation being perpendicular to walls. origin selection rules contrast discussed. results suggest that produce a deteriorating effect on quasiphase matching.

We have performed tests of recent theories for the surface second-harmonic (SH) response a jellium metal by measuring dispersion characteristics SH generation from atomically clean Al(111), Al(110), and Al(100) surfaces. This has been done wavelengths between 565 860 nm, using picosecond-pulse dye-laser beam incident at angles 22.5\ifmmode^\circ\else\textdegree\fi{}, 45\ifmmode^\circ\else\textdegree\fi{}, 67.5\ifmmode^\circ\else\textdegree\fi{}. In all cases, only p-polarized light generated...

The linear optical properties of semiconducting carbon nanotubes are dominated by quasi-one-dimensional excitons formed single electron−hole pairs. Hence, the nonlinear response at high pump levels most likely leads to formation exciton complexes involving several Such would therefore play an important role in, e.g., lasing applications. We demonstrate here that biexciton complex is surprisingly stable for in a wide diameter range. Theoretical predictions signature such states pump−probe...