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In-fibre particle manipulation and device assembly via laser induced thermocapillary convection
摘要： The ability to manipulate in-fibre particles is of technological and scientific significance, yet particle manipulation inside solid environment remains fundamentally challenging. Here we show an accurately controlled, non-contact, size- and material-independent method for manipulating in-fibre particles based on laser-induced thermocapillary convection. The laser liquefaction process transforms the fibre from a solid media into an ideal fluid environment and triggers the in-fibre thermocapillary convection. In-fibre particles, with diameter from submicron to hundreds of microns, can be migrated toward the designated position. The number of particles being migrated, the particle migration velocity and direction can be precisely controlled. As a proof-of-concept, the laser-induced flow currents lead to the migration-to-contact of dislocated in-fibre p- and n-type semiconductor particles and the forming of dual-particle p-n homo- and heterojunction directly in a fibre. This approach not only enables in-fibre device assembly to achieve multi-component fibre devices, but also provide fundamental insight for in-solid particle manipulation.
关键词： in-fibre particle manipulation,p-n junction,laser-induced thermocapillary convection,multi-component fibre devices
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 4th Optoelectronics Global Conference (OGC) - Shenzhen, China (2019.9.3-2019.9.6)] 2019 IEEE 4th Optoelectronics Global Conference (OGC) - Ultra-High-Power and High-Efficiency 905nm Pulsed Laser for LiDAR
摘要： We report the design, fabrication and characterization of ultra-high-power and high-efficiency 905-nm pulsed lasers with four epitaxially stacked emitters connected by tunnel junctions for LiDAR application. The P-side-up submounted multimode lasers produce as high as 150 W at the current of 35 A and environmental temperature of 25°C. At the output power of 111.5 W, the Wall-Plug Efficiency and slope efficiency reach 41.4% and 4.66 W/A, respectively. The measurement shows 284-μm beam width and 12.6-degree horizontal far-field angle (95% power enclosure), indicating high brightness for this device, making it well-suited for long-distance and high-spatial-resolution range finding.
关键词： tunnel junction,temperature performance,ultra-high power,lidar,beam quality,semiconductor laser
更新于2025-09-16 10:30:52
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Effects of P-N Junction Built-In Electric Field on Ir-Led Resistance under Gamma Rays Irradiation
摘要： It is known that the rate of introduction of radiation defects into the Schottky barrier of GaAs and InP diodes depends on the presence of the electric field. The main aim of this research is to study the influence of the built-in electric field at the p-n junction on the resistance of dual AlGaAs heterostructure IR-LEDs under gamma rays irradiation. It is determined that the rate of defects introduction in the presence of built-in electric field or reverse bias at p-n junction is considerably less than the rate of defects introduction into the neutral region without electric field. Then the possible ways of improving the radiation resistance of infrared LEDs are considered.
关键词： heterostructures,p-n junction,AlGaAs,light emitting diodes,gamma ray
更新于2025-09-16 10:30:52
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Temperature Accelerated Life Test and Failure Analysis on Upright Metamorphic Ga <sub/>0.37</sub> In <sub/>0.63</sub> P/Ga <sub/>0.83</sub> In <sub/>0.17</sub> As/Ge Triple Junction Solar Cells
摘要： A temperature accelerated life test on Upright Metamorphic Ga0.37In0.63P/Ga0.83In0.17As/Ge triple‐junction solar cells has been carried out. The acceleration has been accomplished by subjecting the solar cells to temperatures (125, 145 and 165°C) significantly higher than the nominal working temperature inside a concentrator (90°C), while the nominal photo‐current (500×) has been emulated by injecting current in darkness. The failure distributions have been fitted to an Arrhenius–Weibull model resulting in an activation energy of 1.39 eV. Accordingly, a 72 years warranty time for those solar cells for a place like Tucson (AZ, USA), was determined. After the ALT, an intense characterization campaign has been carried out in order to determine the failure origin. We have detected that temperature soak alone is enough to degrade the cell performance by increasing the leakage currents, the series resistance, and the recombination currents. When solar cells were also forward biased an increase of series resistance together with a reduction of short circuit current is detected. The failure analysis shows that: a) several metallization sub‐products concentrate in several regions of front metal grid where they poison the silver, resulting in a two times reduction of the metal sheet resistance; b) the metal/cap layer interface is greatly degraded and there is also a deterioration of the cap layer crystalline quality producing a huge increase of the specific front contact resistance, c) the decrease of short circuit current is mainly due to the GaInP top subcell degradation.
关键词： CPV,upright metamorphic solar cells,triple‐junction solar cells,solar cell reliability,failure analysis
更新于2025-09-16 10:30:52
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The transparent Schottky junction of reduced graphene oxide/SnO <sub/>2</sub> nanoarrays towards enhanced broadband photoresponse
摘要： The rGO/SnO2 nanoarrays (rGO/SnO2 NAs) Schottky junction is synthesized by a series of RF magnetron sputtering, hydrothermal and electrochemical deposition. The unique transparent junction exhibits the broadband photoelectric responses from the ultraviolet to visible light. As shown, the proper rGO/SnO2 NAs display highly transparency of about ~60% and dramatically enhance photoelectric conversion of about ~100 times than that of the initial Schottky junction. Finally, the mechanism of the Schottky junction is investigated.
关键词： reduced graphene oxide,broadband photoresponse,transparent Schottky junction,SnO2 nanoarrays
更新于2025-09-16 10:30:52
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Grain Boundary Josephson Junction Harmonic Mixer Coupled With a Bowtie Loaded Meander Antenna With Zero-Bias Operation
摘要： The high-Tc superconducting (HTS) bicrystal YBa2Cu3O7–δ (YBCO) zero-bias-operation Josephson junction (JJ) harmonic mixer coupled with a bowtie loaded meander antenna (BLMA) is proposed and studied at 0.21 THz. When the JJ mixer coupled with the BLMA, the maximal harmonic number increases up to 146 with the conversion ef?ciency of ?63.6 dB at the bath temperature around 4.6 K compared to a mixer coupled with a log-periodic antenna (LPA) of only a maximal harmonic number of 46 with the conversion ef?ciency of ?71.6 dB. The mixer coupled with the BLMA has a higher order harmonic mixing with a lower local oscillator (LO) power of 1.26 dBm, which further illustrates its superiority to that coupled with a LPA with the LO power of 5.59 dBm. The experiment veri?es the merits of the JJ harmonic mixer operating at zero bias as a promising device in terahertz regions.
关键词： Josephson junction (JJ),meander antenna,zero-bias operation,harmonic mixer
更新于2025-09-16 10:30:52
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Effect of the Irradiation on Optical and Electrical Properties of Triple-Junction Flexible Thin Solar Cells for Space Applications
摘要： The most common multi-junction solar cell arrangement employs the InGaP/InGaAs/Ge configuration, which is usually exploited for high-efficiency space applications. We here test the reliability of a triple-junction device with an innovative low-thickness and flexible configuration: this is investigation is aimed at providing its main macroscopic features which must be taken into account for their applications. Notably, the specific optical and electrical features and the performance variation of these thin solar cells are systematically analyzed, both in begin-of-life (BOL) configuration and after irradiation (end-of-life, EOL) by either electrons or protons. Measurements of I – V curves, with correlated parameters, and of spectral responses (external quantum efficiency) are accomplished on several BOL and EOL samples: this allows to describe the inhomogeneous damage of the subjunctions and to follow the evolution of the solar cell physical quantities as a function of the kind and the amount of irradiation. Finally, photoluminescence emission spectra are measured, pointing out the effect of particle bombardment on luminescent features. Our results show that these innovative solar devices allow for the combination of high specific power, mechanical flexibility, high performance, and strong resistance to particle irradiation, making them an excellent option for space applications.
关键词： multi-junction cells,III-V semiconductors,component cells,irradiated cells,space solar cells
更新于2025-09-16 10:30:52
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Fabrication of an Efficient Planar Organic-Silicon Hybrid Solar Cell with a 150 nm Thick Film of PEDOT: PSS
摘要： Organic–inorganic hybrid solar cells composed of p-type conducting polymer poly (3,4-ethylene-dioxythiophene): polystyrenesulfonate (PEDOT: PSS) and n-type silicon (Si) have gained considerable interest in recent years. From this viewpoint, we present an e?cient hybrid solar cell based on PEDOT: PSS and the planar Si substrate (1 0 0) with the simplest and cost-e?ective experimental procedures. We study and optimize the thickness of the PEDOT: PSS ?lm to improve the overall performance of the device. We also study the e?ect of ethylene glycol (EG) by employing a di?erent wt % as a solvent in the PEDOT: PSS to improve the device’s performance. Silver (Ag) was deposited by electron beam evaporation as the front and rear contacts for the solar cell device. The whole fabrication process was completed in less than three hours. A power conversion e?ciency (PCE) of 5.1%, an open circuit voltage (Voc) of 598 mV, and a ?ll factor (FF) of 58% were achieved.
关键词： single junction solar cells,conducting polymers,hybrid solar cells,ethylene glycol,cost effective
更新于2025-09-16 10:30:52
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Theoretical Study of Proton Radiation Influence on the Performance of a Polycrystalline Silicon Solar Cell
摘要： The aim of this work is to study the behaviour of a silicon solar cell under the irradiation of di?erent ?uences of high-energy proton radiation (10 MeV) and under constant multispectral illumination. Many theoretical et experimental studies of the e?ect of irradiation (proton, gamma, electron, etc.) on solar cells have been carried out. These studies point out the e?ect of irradiation on the behaviour of the solar cell electrical parameters but do not explain the causes of these e?ects. In our study, we explain fundamentally the causes of the e?ects of the irradiation on the solar cells. Taking into account the empirical formula of di?usion length under the e?ect of high-energy particle irradiation, we established new expressions of continuity equation, photocurrent density, photovoltage, and dynamic junction velocity. Based on these equations, we studied the behaviour of some electronic and electrical parameters under proton radiation. Theoretical results showed that the defects created by the irradiation change the carrier distribution and the carrier dynamic in the bulk of the base and then in?uence the solar cell electrical parameters (short-circuit current, open-circuit voltage, conversion e?ciency). It appears also in this study that, at low ?uence, junction dynamic velocity decreases due to the presence of tunnel defects. Obtained results could lead to improve the quality of the junction of a silicon solar cell.
关键词： silicon solar cell,proton radiation,diffusion length,electrical parameters,carrier distribution,junction dynamic velocity
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - St. Petersburg, Russia (2019.10.17-2019.10.18)] 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - A Method for Increasing the Low-Temperature Stability of Steady-State Behavior and Common-Mode Interference Resistance CJFET Dual-Input-Stages
摘要： An original input differential stage circuit (DS) on complementary junction field-effect transistors (CJFET) is proposed. Their main designated area is low-noise analog ICs for operation at low temperatures, including cryogenic ones. The special circuit design for setting steady-state behavior of the DS and its parametric optimization in the LTspice environment provide a relatively high stability of the CJFet steady-state behavior of the input transistors in a wide temperature range. It is shown that, in this case, the common- mode rejection ratio is increased.
关键词： low-temperature electronics,differential operational amplifier,LTspice environment,differential stage,common-mode rejection ratio,junction field-effect transistors
更新于2025-09-16 10:30:52