scholarly journals Edge diffraction, plasmon launching, and universal absorption enhancement in two-dimensional junctions

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Egor Nikulin ◽  
Dmitry Mylnikov ◽  
Denis Bandurin ◽  
Dmitry Svintsov
2015 ◽  
Vol 23 (6) ◽  
pp. 7120 ◽  
Author(s):  
Haomin Song ◽  
Suhua Jiang ◽  
Dengxin Ji ◽  
Xie Zeng ◽  
Nan Zhang ◽  
...  

2014 ◽  
Vol 14 (7) ◽  
pp. 10659-10699
Author(s):  
H. Matsui ◽  
M. Koike ◽  
Y. Kondo ◽  
J. D. Fast ◽  
M. Takigawa

Abstract. Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimation of aerosol direct and indirect effects. In this study, we develop an aerosol module, designated Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can represent these parameters explicitly by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 μm to resolve both aerosol size (12 bins) and BC mixing state (10 bins) for a total of 120 bins. The particles with diameters from 1 to 40 nm are resolved using an additional 8 size bins to calculate NPF. The ATRAS module is implemented in the WRF-chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging and SOA processes over East Asia during the spring of 2009. BC absorption enhancement by coating materials is about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement is estimated to be 10–20% over northern East Asia and 20–35% over southern East Asia. A clear north-south contrast is also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increases CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increases CCN concentrations at lower supersaturations (larger particles) over southern East Asia. Application of ATRAS to East Asia also shows that the impact of each process on each optical and radiative parameter depends strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes under different meteorological conditions and emissions.


2014 ◽  
Vol 14 (18) ◽  
pp. 10315-10331 ◽  
Author(s):  
H. Matsui ◽  
M. Koike ◽  
Y. Kondo ◽  
J. D. Fast ◽  
M. Takigawa

Abstract. Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimations of aerosol direct and indirect effects. In this study, we develop an aerosol module, designated the Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can explicitly represent these parameters by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 μm to resolve both aerosol sizes (12 bins) and BC mixing states (10 bins) for a total of 120 bins. The particles with diameters between 1 and 40 nm are resolved using additional eight size bins to calculate NPF. The ATRAS module is implemented in the WRF-Chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging, and SOA processes over East Asia during the spring of 2009. The BC absorption enhancement by coating materials is about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement is estimated to be 10–20% over northern East Asia and 20–35% over southern East Asia. A clear north–south contrast is also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increases CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increases CCN concentrations at lower supersaturations (larger particles) over southern East Asia. The application of ATRAS in East Asia also shows that the impact of each process on each optical and radiative parameter depends strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes under different meteorological conditions and emissions.


2017 ◽  
Vol 7 (5) ◽  
pp. 1324-1328 ◽  
Author(s):  
Ming Chen ◽  
Ye Zhang ◽  
Yanxia Cui ◽  
Fan Zhang ◽  
Wei Qin ◽  
...  

2020 ◽  
Vol 7 (7) ◽  
pp. 191926
Author(s):  
Mohammed Shahriar Sabuktagin ◽  
Khairus Syifa Hamdan

Two-dimensional finite difference time domain (FDTD) simulations were performed for evaluating optical absorption enhancement and loss effects of triangular silver (Ag) nanowires embedded in silicon (Si) thin-film photovoltaic device structures. Near-bandgap absorption enhancement in Si was much larger than the reported values of other nanostructures from similar simulations. A nanowire with equal sides of 20 nm length showed 368-fold absorption enhancement whereas only 5× and 15× enhancement were reported for solid spherical and two-dimensional core-shell type nanostructures, respectively. Undesirable absorption loss in the metal of the nanowire was 3.55× larger than the absorption in Si which was comparable to the value reported for the spherical nanoparticle. Interestingly, as the height of the nanowire was increased to form a sharper tip, absorption loss showed a significant drop. For a nanowire with 20 nm base and 20 nm height, absorption loss was merely 1.91× larger than the absorption in Si at the 840 nm plasmon resonance. This drop could be attributed to weaker plasmon resonance manifested by lower metallic absorption in the spatial absorption map of the nanowire. However, absorption enhancement in Si was still large due to strong plasmonic fields at the sharper and longer tip, which was effective in enhancing absorption over a larger area in Si. Our work shows that the shape of a nanostructure and its optimization can significantly affect plasmonic absorption enhancement and loss performance in photovoltaic applications.


2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Bong Jae Lee ◽  
Yu-Bin Chen ◽  
Sunwoo Han ◽  
Feng-Cheng Chiu ◽  
Hyun Jin Lee

The direct utilization of solar radiation has been considered a promising energy source because of its abundance, sustainability, and cleanness. The conversion of solar radiation into usable heat largely depends on the absorption characteristics of a solar thermal collector. In the present study, we conducted design analysis of a wavelength-selective absorber composed of a two-dimensional Nickel grating, a thin SiO2 film, and a Nickel substrate. Dimensions of the two-dimensional grating were determined with the Taguchi method, which optimized the spectral absorptance for both polarizations. The spectral absorptance demonstrated a broad-band plateau within the visible and the near-infrared spectral region, but it was significantly suppressed at longer wavelengths. Moreover, the absorptance plateau was nearly insensitive to the incident orientation of solar radiation. Physical mechanisms of the absorption enhancement were elucidated with the local magnetic field distribution.


2018 ◽  
Vol 25 (2) ◽  
pp. 419-424 ◽  
Author(s):  
Jun Wu

The polarization-independent enhanced absorption effect of graphene in the near-infrared range is investigated. This is achieved by placing a graphene square array on top of a dielectric square array backed by a two-dimensional multilayer grating. Total optical absorption in graphene can be attributed to critical coupling, which is achieved through the combined effect of guided-mode resonance with the dielectric square array and the photonic band gap with the two-dimensional multilayer grating. To reveal the physical origin of such a phenomenon, the electromagnetic field distributions for both polarizations are illustrated. The designed graphene absorber exhibits near-unity polarization-independent absorption at resonance with an ultra-narrow spectrum. Moreover, the polarization-independent absorption can be tuned simply by changing the geometric parameters. The results may have promising potential for the design of graphene-based optoelectronic devices.


2010 ◽  
Vol 636-637 ◽  
pp. 855-859 ◽  
Author(s):  
Ya Lin Lu ◽  
Ling Li ◽  
Karen A. Reinhardt

Enhancing absorption of solar cells over the solar spectrum is one of the most important ways to improve such devices’ performances. In this research, two-dimensional surface photonic designs were suggested to introduce rotationally distributed reciprocal vectors, which will match the guiding modes of the thin planar layer of an active material, and thus to further couple the incident light laterally into the layer. This allows the use of a fewer amount of active materials, increases the devices’ angle acceptance, and reduces costs for both fabrication and system installation.


Sign in / Sign up

Export Citation Format

Share Document