scholarly journals Individually Switchable InGaN/GaN Nano-LED Arrays as Highly Resolved Illumination Engines

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1829
Author(s):  
Katarzyna Kluczyk-Korch ◽  
Sergio Moreno ◽  
Joan Canals ◽  
Angel Diéguez ◽  
Jan Gülink ◽  
...  
Keyword(s):  
Near Field ◽  
Spot Size ◽  
Contact Lines ◽  
Resolution Limit ◽  
Light Emitting ◽  
Led Array ◽  
Display Technology ◽  
Materials Used ◽  
Difference Time ◽  
Led Arrays

GaN-based light emitting diodes (LEDs) have been shown to effectively operate down to nanoscale dimensions, which allows further downscaling the chip-based LED display technology from micro- to nanoscale. This brings up the question of what resolution limit of the illumination pattern can be obtained. We show two different approaches to achieve individually switchable nano-LED arrays. We evaluated both designs in terms of near-field spot size and optical crosstalk between neighboring pixels by using finite difference time domain (FDTD) simulations. The numerical results were compared with the performance data from a fabricated nano-LED array. The outcome underlines the influence of geometry of the LED array and materials used in contact lines on the final illumination spot size and shape.

Localized Light Focusing and Super Resolution Readout via Chalcogenide Thin Film

2006 ◽  
Vol 918 ◽  
Author(s):  
Junji Tominaga ◽  
Paul Fons ◽  
Takayuki Shima ◽  
Kazuma Kurihara ◽  
Takashi Nakano ◽  
...  
Keyword(s):  
Finite Difference Time Domain ◽  
Near Field ◽  
Super Resolution ◽  
Spot Size ◽  
Optical Disc ◽  
Chalcogenide Film ◽  
Fdtd Simulations ◽  
Light Focusing ◽  
Difference Time ◽  
Chalcogenide Thin Film

AbstractWe have demonstrated that certain chalcogenide layers within a spinning super-RENS optical disc allow to squeeze the 650 nm laser beam to a spot size as fine as 50 nm using a 15-nm chalcogenide film. The near-field light was focused at a depth of just over 30 nm after passing through a chalcogenide film. Finite-difference time-domain (FDTD) simulations also reproduced these results. We suggest that a conductive ring aperture generated in the chalcogenide layers plays an important role in the localized light focusing.

scholarly journals The investigation of the features of focusing vortex super-Gaussian beams with a variable-height diffractive axicon

2021 ◽  
Vol 45 (2) ◽  
pp. 214-221
Author(s):  
D.A. Savelyev
Keyword(s):  
Gaussian Beam ◽  
Circular Polarization ◽  
Focal Spot ◽  
Near Field ◽  
Optical Element ◽  
Spot Size ◽  
Minimum Size ◽  
Focal Spot Size ◽  
Diffractive Axicon ◽  
Difference Time

Spatial intensity distributions of the Laguerre-superGauss modes (1,0) as well as a super-Gaussian beam with radial and circular polarization were investigated versus changes in the height of a diffractive axicon. The height of the relief of the optical element varied from 0.25λ to 3λ. The modeling by a finite-difference time-domain method showed that variations in the height of the diffractive axicon significantly affect the diffraction pattern in the near field of the axicon. The smallest focal spot size for a super-Gaussian beam was obtained for radial polarization at a height equal to two wavelengths. The minimum size of the focal spot for the Laguerre-superGauss mode (1,0) was obtained for circular "–" polarization with an element height equal to a quarter of the wavelength.

Statistical analysis of achievable resolution limit in the near field source localization context

2012 ◽  
Vol 92 (2) ◽  
pp. 547-552 ◽  
Author(s):  
Mohammed Nabil El Korso ◽  
Rémy Boyer ◽  
Alexandre Renaux ◽  
Sylvie Marcos
Keyword(s):  
Statistical Analysis ◽  
Source Localization ◽  
Near Field ◽  
Resolution Limit ◽  
Field Source

scholarly journals Unravelling the electron injection/transport mechanism in organic light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tsubasa Sasaki ◽  
Munehiro Hasegawa ◽  
Kaito Inagaki ◽  
Hirokazu Ito ◽  
Kazuma Suzuki ◽  
...  
Keyword(s):  
Work Function ◽  
Transport Mechanism ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Materials Used

AbstractAlthough significant progress has been made in the development of light-emitting materials for organic light-emitting diodes along with the elucidation of emission mechanisms, the electron injection/transport mechanism remains unclear, and the materials used for electron injection/transport have been basically unchanged for more than 20 years. Here, we unravelled the electron injection/transport mechanism by tuning the work function near the cathode to about 2.0 eV using a superbase. This extremely low-work function cathode allows direct electron injection into various materials, and it was found that organic materials can transport electrons independently of their molecular structure. On the basis of these findings, we have realised a simply structured blue organic light-emitting diode with an operational lifetime of more than 1,000,000 hours. Unravelling the electron injection/transport mechanism, as reported in this paper, not only greatly increases the choice of materials to be used for devices, but also allows simple device structures.

scholarly journals Waiting for Act 2: what lies beyond organic light-emitting diode (OLED) displays for organic electronics?

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 31-40
Author(s):  
Stephen R. Forrest
Keyword(s):  
Organic Electronics ◽  
Light Emitting Diode ◽  
Electronic Devices ◽  
Organic Electronic Devices ◽  
Organic Electronic ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Semiconductor Thin Films ◽  
Display Technology

AbstractOrganic light-emitting diode (OLED) displays are now poised to be the dominant mobile display technology and are at the heart of the most attractive televisions and electronic tablets on the market today. But this begs the question: what is the next big opportunity that will be addressed by organic electronics? We attempt to answer this question based on the unique attributes of organic electronic devices: their efficient optical absorption and emission properties, their ability to be deposited on ultrathin foldable, moldable and bendable substrates, the diversity of function due to the limitless palette of organic materials and the low environmental impact of the materials and their means of fabrication. With these unique qualities, organic electronics presents opportunities that range from lighting to solar cells to medical sensing. In this paper, we consider the transformative changes to electronic and photonic technologies that might yet be realized using these unconventional, soft semiconductor thin films.

Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

2014 ◽  
Vol 602-605 ◽  
pp. 3359-3362
Author(s):  
Chun Li Zhu ◽  
Jing Li
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Incident Light ◽  
Near Field ◽  
Three Dimensional ◽  
Polarization Direction ◽  
Near Field Imaging ◽  
Difference Time ◽  
Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

Design of a Near-Field Probe for Optical Recording Using a 3-Dimensional Finite Difference Time Domain Method

2000 ◽  
Vol 39 (Part 1, No. 2B) ◽  
pp. 973-975 ◽  
Author(s):  
Kusato Hirota ◽  
Tom D. Milster ◽  
Yan Zhang ◽  
J. Kevin Erwin
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Near Field ◽  
Optical Recording ◽  
Time Domain Method ◽  
3 Dimensional ◽  
Domain Method ◽  
Difference Time

Trapping of Nano-Particles Using a Near-Field Optical Fiber Probe

2012 ◽  
Vol 516 ◽  
pp. 90-95
Author(s):  
Bing Hui Liu ◽  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Near Field ◽  
Fdtd Method ◽  
Laser Wavelength ◽  
Nano Particles ◽  
Minimum Size ◽  
Fiber Probe ◽  
Circular Shape ◽  
Optical Fiber Probe ◽  
Fibre Probe ◽  
Difference Time

By employing a generalization of the conservation law for momentum using the finite difference time domain (FDTD) method, the feasibility of using a near-field optical fibre probe to create near-field optical trapping is investigated. Numerical results indicate that the scheme is able to trap nanoparticles with diameters of tens of nanometres in a circular shape with lower laser intensity. Using the built system with a tapered metal-coated fibre probe, 120 nm polystyrene particles are trapped in a multi-circular shape with a minimum size of 400 nm. They are at a resolution of λ/7 (λ: laser wavelength) and d (d: tip diameter of fiber probe), respectively.

scholarly journals Operando direct observation of spin-states and charge-trappings of blue light-emitting-diode materials in thin-film devices

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fumiya Osawa ◽  
Kazuhiro Marumoto
Keyword(s):  
Blue Light ◽  
High Performance ◽  
Density Functional ◽  
Light Emitting Diode ◽  
Green Light ◽  
Spin States ◽  
Light Emitting ◽  
Full Color ◽  
Color Displays ◽  
Materials Used

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

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