Faster than the Speed of Light Is a Quantum Phenomena

Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 108 m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.

On Electron Clouds and Light

The wave equation of the electron, recently improved, allows physics to obtain all the quantum numbers and other results explaining the hydrogen spectrum. The Pauli exclusion principle then gives the description of electron clouds used in chemistry. The relativistic wave equation is associated with a Lagrangian density, thus also with an energy-momentum tensorial density. The wave of an electron cloud adds these energy-momentum densities, while photons in light are precisely those differences between such energy-momentum densities.

On a Heuristic Viewpoint Concerning the Conversion and Transformation of Sound into Light

In the study of Terrestrial Gamma-ray Flashes (TGFs) and Sonoluminescence, we observe parallels with larger cosmic events. Specifically, sonoluminescence involves the rapid collapse of bubbles, which closely resembles gravitational collapse in space. This observation suggests the potential formation of low-density quantum black holes. These entities, which might be related to dark matter, are thought to experience a kind of transient evaporation similar to Hawking radiation seen in cosmic black holes. Consequently, sonoluminescence could be a valuable tool for investigating phenomena typically linked to cosmic scale events. Furthermore, the role of the Higgs boson is considered in this context, possibly connecting it to both TGFs and sonoluminescence. This research could enhance our understanding of the quantum mechanics of black holes and their relation to dark matter on Earth.

Internal quantum efficiency drop induced by the heat generation inside of light emitting diodes (LEDs)

The reasons for low output power of AlGalnP Light Emitting Diodes （LEDs） have been analysed. LEDs with AlGaInP material have high internal but low external quantum efficiency and much heat generated inside especially at a large injected current which would reduce both the internal and external quantum efficiencies. Two kinds of LEDs with the same active region but different window layers have been fabricated. The new window layer composed of textured 0.5 μm GaP and thin Indium-Tin-Oxide film has shown that low external quantum efficiency （EQE） has serious impaction on the internal quantum efficiency （IQE）, because the carrier distribution will change with the body temperature increasing due to the heat inside, and the test results have shown the evidence of LEDs with lower output power and bigger wavelength red shift.

Improved blue quantum dot light-emitting diodes via chlorine passivated ZnO nanoparticle layer

In blue quantum dot light emitting diodes(QLEDs),electron injection is insufficient,which would degrade device efficiency and stability.Herein,we employ chlorine passivated ZnO nanoparticles as electron transport layer to facilitate electron injection into QDs effectively.Moreover,it suppresses exciton quenching at the QD/ZnO interface by blocking charge transfer channel.As a result,the maximum external quantum efficiency of blue QLED was increased from 2.55%to 4.60%,and the operation lifetime of blue QLED was nearly 4 times longer than that of the control device.Our work indicates that election injection plays an important role in blue QLED efficiency and stability.

Performance improvement of InGaN/GaN multiple quantum well visible-light photodiodes by optimizing TEGa flow

The performance of an InGaN/GaN multiple quantum well（MQW） based visible-light Schottky photodiode（PD）is improved by optimizing the source flow of TEGa during In Ga N QW growth. The samples with five-pair InGaN/GaN MQWs are grown on sapphire substrates by metal organic chemical vapor deposition. From the fabricated Schottky-barrier PDs, it is found that the smaller the TEGa flow, the lower the reverse-bias leakage is. The photocurrent can also be enhanced by depositing the In GaN QWs with using lower TEGa flow. A high responsivity of 1.94 A/W is obtained at 470 nm and -3-V bias in the PD grown with optimized TEGa flow. Analysis results show that the lower TEGa flow used for depositing In Ga N may lead to superior crystalline quality with improved InGaN/GaN interface, and less structural defects related non-radiative recombination centers formed in the MQWs.

Metal–organic–vapor phase epitaxy of InGaN quantum dots and their applications in light-emitting diodes

InGaN quantum dot is a promising optoelectronic material, which combines the advantages of low-dimensional and wide-gap semiconductors. The growth of InGaN quantum dots is still not mature, especially the growth by metal--organic- vapor phase epitaxy （MOVPE）, which is challenge due to the lack of, itin-situ monitoring tool. In this paper, we reviewed the development of InGaN quantum dot growth by MOVPE, including our work on growth of near-UV, green, and red InGaN quantum dots. In addition, we also introduced the applications of InGaN quantum dots on visible light emitting diodes.

基于QPSO-LightGBM网络资产脆弱性评估模型

为有效减少网络安全事件造成的损失,并对高风险网络资产进行漏洞评估,提出了一种基于量子粒子群轻量级梯度升降算法(QPSO-LightGBM:Quantum Particle Swarm Optimization-Light Gradient Boosting Machine)的多分类预测模型。该模型通过对少量过采样技术(MOTE:Minority Oversampling)进行合成从而达到数据平衡,采用量子粒子群算法(QPSO:Quantum Particle Swarm Optimization)实现参数的自动最优化,并使用LightGBM进行建模,进而实现网络资产的多分类预测。为验证模型的有效性,将所提模型与其他算法模型进行了比对,实验结果表明,该模型在各类预测性能指标上都取得了较好的效果。

Blue InGaN light-emitting diodes with dip-shaped quantum wells

InGaN based light-emitting diodes （LEDs） with dip-shaped quantum wells and conventional rectangular quantum ~lls are numerically investigated by using the APSYS simulation software. It is found that the structure with dip- aped quantum wells shows improved light output power, lower current leakage and less efficiency droop. Based on Lmerical simulation and analysis, these improvements on the electrical and the optical characteristics are attributed ainly to the alleviation of the electrostatic field in dip-shaped InGaN/GaN multiple quantum wells （MQWs）.

Near-infrared lead chalcogenide quantum dots:Synthesis and applications in light emitting diodes

This paper reviews the recent progress in the synthesis of near-infrared(NIR) lead chalcogenide(PbX;PbX = PbS,PbSe, PbTe) quantum dots(QDs) and their applications in NIR QDs based light emitting diodes(NIR-QLEDs). It summarizes the strategies of how to synthesize high efficiency PbX QDs and how to realize high performance Pb X based NIR-QLEDs.

Fabrication and optical properties of InGaN/GaN multiple quantum well light emitting diodes with amorphous BaTiO_3 ferroelectric film

BaTiO3 （BTO） ferroelectric thin films are prepared by the sol,el method. The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode （LED） with amorphous BTO ferroelectric thin film are studied. The photolumineseence （PL） of the BTO ferroelectric film is attributed to the structure. The ferroeleetric film which annealed at 673 K for 8 h has the better PL property. The peak width is about 30 nm from 580 nm to 610 nm, towards the yellow region. The mixed electroluminescence （EL） spectrum of InGaN/GaN multiple quantum well LED with 150-nm thick amorphous BTO ferroelectric thin film displays the blue-white light. The Commission Internationale De L＇Eclairage （CIE） coordinate of EL is （0.2139, 0.1627）. EL wavelength and intensity depends on the composition, microstructure and thickness of the ferroelectric thin film. The transmittance of amorphous BTO thin film is about 93% at a wavelength of 450 nm-470 nm. This means the amorphous ferroelectrie thin films can output more blue-ray and emission lights. In addition, the amorphous ferroelectric thin films can be directly fabricated without a binder and used at higher temperatures （200 ℃-400 ℃）. It is very favourable to simplify the preparation process and reduce the heat dissipation requirements of an LED. This provides a new way to study LEDs.

Absorption and slow light effect of pulsed light in a triple semiconductor quantum well

Under the condition of two different cases, the absorption of a pulsed probe field and its slow propagation in a triple semiconductor quantum well are investigated. The result shows that semiconductor medium becomes transparent due to the action of control field. Another result shows that by choosing appropriate physical parameters, the slow propagation of the input field can be achieved. The proposed scheme has some potential applications and may lead to the development of the controlled technique of optical buffers and optical delay lines.

Efficiency droop alleviation in blue light emitting diodes using the InGaN/GaN triangular-shaped quantum well

The InGaN/GaN blue light emitting diode（LED） is numerically investigated using a triangular-shaped quantum well model,which involves analysis on its energy band,carrier concentration,overlap of electron and hole wave functions,radiative recombination rate,and internal quantum efficiency.The simulation results reveal that the InGaN/GaN blue light emitting diode with triangular quantum wells exhibits a higher radiative recombination rate than the conventional light emitting diode with rectangular quantum wells due to the enhanced overlap of electron and hole wave functions（above 90%） under the polarization field.Consequently,the efficiency droop is only 18% in the light emitting diode with triangular-shaped quantum wells,which is three times lower than that in a conventional LED.

Visualizing light-to-electricity conversion process in InGaN/GaN multi-quantum wells with a p-n junction

Absorption and carrier transport behavior plays an important role in the light-to-electricity conversion process, which is difficult to characterize. Here we develop a method to visualize such a conversion process in the InGaN/GaN multiquantum wells embedded in a p-n junction. Under non-resonant absorption conditions, a photocurrent was generated and the photoluminescence intensity decayed by more than 70% when the p-n junction out-circuit was switched from open to short. However, when the excitation photon energy decreased to the resonant absorption edge, the photocurrent dropped drastically and the photoluminescence under open and short circuit conditions showed similar intensity. These results indicate that the escaping of the photo-generated carriers from the quantum wells is closely related to the excitation photon energy.

Application of Quantum Dots in Display:The Milestones of Quantum Dots Light Emitting Displays

We reviewed the key advantages and development of the QD-display and other light applications based on their color purity,stability,and solution processisibility.Analysis of quantum dot based LEDs and the main challenges facing in this field,such as QD luminescence quenching,QD charging in thin films,and the external quantum efficiency was presented in detail.The description about how different optical down-conversion and structures enabled researchers to overcome these challenges and to commercialize the products to achieve the desirable CRI and color temperature was presented.The recent developments about how to overcome these difficulties have also been discussed in this article.

Quantum light source devices of In(Ga)As semiconductor self-assembled quantum dots

A brief introduction of semiconductor self-assembled quantum dots (QDs) applied in single-photon sources is given. Single QDs in confined quantum optical microcavity systems are reviewed along with their optical properties and coupling characteristics. Subsequently, the recent progresses in In(Ga)As QDs systems are summarized including the preparation of quantum light sources, multiple methods for embedding single QDs into different microcavities and the scalability of single-photon emitting wavelength. Particularly, several In(Ga)As QD single-photon devices are surveyed including In(Ga)As QDs coupling with nanowires, InAs QDs coupling with distributed Bragg reflection microcavity and the In(Ga)As QDs coupling with micropillar microcavities. Furthermore, applications in the field of single QDs technology are illustrated, such as the entangled photon emission by spontaneous parametric down conversion, the single-photon quantum storage, the chip preparation of single-photon sources as well as the single-photon resonance-fluorescence measurements.

Sputtered gold nanoparticles enhanced quantum dot light-emitting diodes

Surface plasmonic effects of metallic particles have been known to be an effective method to improve the perfor- mances of light emitting didoes. In this work, we report the sputtered Au nanoparticles enhanced electroluminescence in inverted quantum dot light emitting diodes （ITO/Au NPs/ZnMgO/QDs/TFB/PEDOT：PSS/A1）. By combining the time- resolved photoluminescence, transient electroluminescence, and ultraviolet photoelectron spectrometer measurements, the enhancement of the internal field enhanced exciton coupling to surface plasmons and the electron injection rate increasing with Au nanoparticles＇ incorporation can be explained. Phenomenological numerical calculations indicate that the electron mobility of the electron transport layer increases from 1.39 ×10-5 cm2/V-s to 1.91 ×10-5 cm2/V-s for Au NPs modified device. As a result, the maximum device luminescence is enhanced by 1.41 fold （from 14600 cd/cm2 to 20720 cd/cm2） and maximum current efficiency is improved by 1.29 fold （from 3.12 cd/A to 4.02 cd/A）.

Optical anisotropy and the direction of polarization of exciton emissions in a semiconductor quantum dot:Effect of heavy-and light-hole mixing

The dependence of the directions of polarization of exciton emissions, fine structure splittings （FSS）, and polarization anisotropy on the light- and heavy-hole （LH-HH） mixing in semiconductor quantum dots （QDs） is investigated using a mesoscopic model. In general, all QDs have a four-fold exciton ground state. Two exciton states have directions of polarization in the growth-plane, while the other two are along the growth direction of the QD. The LH-HH mixing does affect the FSS and polarization anisotropy of bright exciton states in the growth-plane in the low symmetry QDs （e.g., C2v, CS, C1 ）, while it has no effect on the FSS and polarization anisotropy in high symmetry QDs （e.g., C3V, D2d）. When the hole ground state is pure HH or LH, the bright exciton states in the growth-plane are normal to each other. The LH-HH mixing affects the relative intensities and directions of bright exciton states in the growth-plane of the QD. The polarization anisotropy of exciton emissions in the growth-plane of the QD is independent of the phase angle of LH-HH mixing but strongly depends on the magnitude of LH-HH mixing in low symmetry QDs.

Efficiency droop suppression in GaN-based light-emitting diodes by chirped multiple quantum well structure at high current injection

Gallium nitride （GaN） based light-emitting diodes （LEDs） with chirped multiple quantum well （MQW） structures have been investigated experimentally and numerically in this paper. Compared to conventional LEDs with uniform quantum wells （QWs）, LEDs with chirped MQW structures have better internal quantum efficiency （IQE） and carrier injection efficiency. The droop ratios of LEDs with chirped MQW structures show a remarkable improvement at 600 mA/mm2, reduced down from 28.6% （conventional uniform LEDs） to 23.7% （chirped MQWs-a） and 18.6% （chirped MQWs-b）, respectively. Meanwhile, the peak IQE increases from 76.9% （uniform LEDs） to 83.7% （chirped MQWs-a） and 88.6% （chirped MQWs-b）. The reservoir effect of chirped MQW structures is the significant reason as it could increase hole injection efficiency and radiative recombination. The leakage current and Auger recombination of chirped MQW structures can also be suppressed. Furthermore, the chirped MQWs-b structure with lower potential barriers can enhance the reservoir effect and obtain further improvement of the carrier injection efficiency and radiative recombination, as well as further suppressing efficiency droop.