Manipulating the directional emission of monolayer semiconductors by dielectric nanoantenna arrays

2021 ◽  
Author(s):  
Pengbo Liu ◽  
Zhenghe Zhang ◽  
Man Lang ◽  
Wanli Lu ◽  
Ping Bai ◽  
...  
Keyword(s):  
Strong Field ◽  
Field Enhancement ◽  
Poor Quality ◽  
Large Area ◽  
Light Emitting Devices ◽  
Directional Emission ◽  
Si Nanoparticle ◽  
High Efficient ◽  
Efficient Scheme ◽  
Different Diameters

Abstract Collective Mie resonances in silicon (Si) nanoparticle arrays (NPAs) feature low absorption losses and strong field enhancement extending to a large area. They provide a high-efficient scheme to manipulate the emission properties of monolayer semiconductors. However, the poor quality factor of the current reported Si NPA limits the performance of light-emitting devices. It is mainly due to the constituent materials of nanoparticles being amorphous or polycrystalline silicon, which have higher absorption coefficients in comparison with monocrystalline silicon (c-Si) among the visible band. This invited paper demonstrates a versatile technique to integrate the atomic layers onto the c-Si NPA. We show that our method can fully preserve the monolayer sample. We further investigate the directional emission tailored by the NPA with different diameters by combining back-focal-plane imaging and reciprocity simulations. The flexible tune of the geometry parameters of NPAs can offer many possibilities to control and manipulate the emission from monolayer semiconductors by engineering their photonic environments.

Engineering the shape of Zinc Oxide crystals via sonochemical or hydrothermal solution-based methods

2008 ◽  
Vol 1087 ◽  
Author(s):  
Marco Palumbo ◽  
Simon J. Henley ◽  
Thierry Lutz ◽  
Vlad Stolojan ◽  
David Cox ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Good Control ◽  
Transparent Conductors ◽  
Zno Nanostructures ◽  
Large Area ◽  
Light Emitting Devices ◽  
Wide Range ◽  
Solution Methods

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.

scholarly journals Terahertz quantum plasmonics at nanoscales and angstrom scales

Nanophotonics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 435-451 ◽  
Author(s):  
Taehee Kang ◽  
Young-Mi Bahk ◽  
Dai-Sik Kim
Keyword(s):  
Electron Tunneling ◽  
Strong Field ◽  
Field Enhancement ◽  
Dipole Antenna ◽  
Strong Light ◽  
Metallic Structures ◽  
Terahertz Pulses ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Quantum Phenomena

AbstractThrough the manipulation of metallic structures, light–matter interaction can enter into the realm of quantum mechanics. For example, intense terahertz pulses illuminating a metallic nanotip can promote terahertz field–driven electron tunneling to generate enormous electron emission currents in a subpicosecond time scale. By decreasing the dimension of the metallic structures down to the nanoscale and angstrom scale, one can obtain a strong field enhancement of the incoming terahertz field to achieve atomic field strength of the order of V/nm, driving electrons in the metal into tunneling regime by overcoming the potential barrier. Therefore, designing and optimizing the metal structure for high field enhancement are an essential step for studying the quantum phenomena with terahertz light. In this review, we present several types of metallic structures that can enhance the coupling of incoming terahertz pulses with the metals, leading to a strong modification of the potential barriers by the terahertz electric fields. Extreme nonlinear responses are expected, providing opportunities for the terahertz light for the strong light–matter interaction. Starting from a brief review about the terahertz field enhancement on the metallic structures, a few examples including metallic tips, dipole antenna, and metal nanogaps are introduced for boosting the quantum phenomena. The emerging techniques to control the electron tunneling driven by the terahertz pulse have a direct impact on the ultrafast science and on the realization of next-generation quantum devices.

Formation, Optical Properties and Applications of Edge Gold-Coated Silver Nanoprisms

2015 ◽  
Vol 1737 ◽  
Author(s):  
Mohammad M. Shahjamali ◽  
Michael Salvador ◽  
Negin Zaraee
Keyword(s):  
High Stability ◽  
Light Harvesting ◽  
Strong Field ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
High Yield ◽  
Bulk Heterojunctions ◽  
Silver Nanoprisms ◽  
Photovoltaic Applications ◽  
Microscopic Techniques

ABSTRACTA facile, high-yield synthesis of edge gold-coated silver nanoprisms (GSNPs) with a gold nanoframe as thin as 1.7 nm and their comprehensive characterizations by using various spectroscopic and microscopic techniques is introduced. The GSNPs exhibit remarkably higher stability than silver nanoprisms (SNPs) and are therefore explored as effective optical antennae for light-harvesting applications. When embedded into a bulk heterojunctions film of P3HT:PCBM, plasmonic GSNPs with a localized surface plasmon resonance (LSPR) around 500 nm can effectively act as optical antennae to enhance light harvesting in the active layer. As a result, we measured up to 7-fold enhancement in the polaron generation yield through photoinduced absorption spectroscopy. Owing to the high stability and strong field enhancement, the presented GSNPs feature great potential as plasmonic probes for photovoltaic applications and LSPR sensing.

scholarly journals Large-area printing of ferroelectric surface and super-domains for efficient solar water splitting

2020 ◽  
Author(s):  
Yu Tian ◽  
Yaqing Wei ◽  
Minghui Pei ◽  
Rongrong Cao ◽  
Zhenao Gu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Electric Fields ◽  
Electronic Structures ◽  
Active Sites ◽  
Large Area ◽  
Solar Water Splitting ◽  
High Efficient ◽  
Catalytic Sites ◽  
Order Of Magnitude ◽  
Magnitude Increase

Abstract Surface electronic structures of the photoelectrodes determine the activity and efficiency of the photoelectrochemical water splitting, but the controls of their surface structures and interfacial chemical reactions remain challenging. Here, we use ferroelectric BiFeO3 as a model system to demonstrate an efficient and controllable water splitting reaction by large-area constructing the hydroxyls-bonded surface. The up-shift of band edge positions at this surface enables and enhances the interfacial holes and electrons transfer through the hydroxyl-active-sites, leading to simultaneously enhanced oxygen and hydrogen evolutions. Furthermore, printing of ferroelectric super-domains with microscale checkboard up/down electric fields separates the distribution of reduction/oxidation catalytic sites, enhancing the charge separation and giving rise to an order of magnitude increase of the photocurrent. This large-area printable ferroelectric surface and super-domains offer an alternative platform for controllable and high-efficient photocatalysis.

scholarly journals Strong field enhancement in individual Φ-shaped dielectric nanostructures based on anapole mode resonances

2020 ◽  
Vol 28 (1) ◽  
pp. 570 ◽  
Author(s):  
Jiepeng Wu ◽  
Fanwei Zhang ◽  
Qiang Li ◽  
Qianbin Feng ◽  
Yu Wu ◽  
...  
Keyword(s):  
Strong Field ◽  
Field Enhancement

scholarly journals Methods for measuring the local emission characteristics of CNT based multi-tip emitters

2021 ◽  
Vol 2103 (1) ◽  
pp. 012116
Author(s):  
E O Popov ◽  
A G Kolosko ◽  
S V Filippov ◽  
S A Ponyaev
Keyword(s):  
Enhancement Factor ◽  
Field Enhancement ◽  
Emission Characteristics ◽  
Large Area ◽  
Software Complex ◽  
Emission Area ◽  
Current Voltage ◽  
Local Emission ◽  
Current Voltage Characteristics ◽  
Comparison Of The Results

Abstract The work is aimed at obtaining microscopic emission characteristics of individual emission sites of a multi-tip field cathode or large-area emitter (LAFE) based on processing the current-voltage characteristics and emission glow patterns. Processing was carried out on a hardware-software complex for the study of field emission characteristics in real time. The calculation of the microscopic characteristics of the local emission sites — the field enhancement factor and emission area — was carried out by several different algorithms. A comparison of the results showed that the algorithms gave close values of the characteristics, which increases the reliability of the estimates made.

scholarly journals Strong field enhancement and light-matter interactions with all-dielectric metamaterials based on split bar resonators

2014 ◽  
Vol 22 (25) ◽  
pp. 30889 ◽  
Author(s):  
Jianfa Zhang ◽  
Wei Liu ◽  
Zhihong Zhu ◽  
Xiaodong Yuan ◽  
Shiqiao Qin
Keyword(s):  
Strong Field ◽  
Field Enhancement

scholarly journals Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

2018 ◽  
Vol 9 ◽  
pp. 2306-2314 ◽  
Author(s):  
Valerio F Gili ◽  
Lavinia Ghirardini ◽  
Davide Rocco ◽  
Giuseppe Marino ◽  
Ivan Favero ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Near Infrared ◽  
Strong Field ◽  
Second Harmonic ◽  
Near Field ◽  
Field Enhancement ◽  
High Refractive Index ◽  
Plasmonic Nanostructures ◽  
Ohmic Losses ◽  
Order Of Magnitude

Background: Dielectric nanoantennas have recently emerged as an alternative solution to plasmonics for nonlinear light manipulation at the nanoscale, thanks to the magnetic and electric resonances, the strong nonlinearities, and the low ohmic losses characterizing high refractive-index materials in the visible/near-infrared (NIR) region of the spectrum. In this frame, AlGaAs nanoantennas demonstrated to be extremely efficient sources of second harmonic radiation. In particular, the nonlinear polarization of an optical system pumped at the anapole mode can be potentially boosted, due to both the strong dip in the scattering spectrum and the near-field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid antenna based on an AlGaAs nanopillar surrounded by a gold ring, which merges in a single platform the strong field confinement typically produced by plasmonic antennas with the high nonlinearity and low loss characteristics of dielectric nanoantennas. This platform allows enhancing the coupling of light to the nanopillar at coincidence with the anapole mode, hence boosting both second- and third-harmonic generation conversion efficiencies. More than one order of magnitude enhancement factors are measured for both processes with respect to the isolated structure. Conclusion: The present results reveal the possibility to achieve tuneable metamixers and higher resolution in nonlinear sensing and spectroscopy, by means of improved both pump coupling and emission efficiency due to the excitation of the anapole mode enhanced by the plasmonic nanoantenna.

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