- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Effect of PbS quantum dot-doped polysulfide nanofiber gel polymer electrolyte on efficiency enhancement in CdS quantum dot-sensitized TiO2 solar cells
摘要： Quantum dot-sensitized solar cells (QDSSCs) are among the most promising low cost third generation solar cells. Semiconductor quantum dots have unique properties such as high molar extinction coefficients, tunable energy gap by the quantum confinement effect and the ability of multiple exciton generation. In this study, stable CdS QDSSCs were fabricated by using polysulfide liquid electrolytes and also by using cellulose acetate nanofiber-based gel electrolytes. Incorporation of PbS Q dots to the liquid or gel electrolyte showed a significant enhancement in solar cell efficiency. Under the simulated light of 100 mW cm-1 the efficiency of the polysulfide liquid electrolyte based CdS QD solar cells increased from 1.19% to 1.51% and the efficiency of the nanofibre gel electrolyte based CdS QD solar cells increased from 0.94 % to 1.46% due to the incorporation of 5% (wt/wt) PbS Q dots into the respective electrolytes. The efficiency increase has been attributed to the increase in short circuit photocurrent density due to increased sulfide ion (S2-) conductivity evidently caused by indirect ionic dissociation facilitated by PbS QDs.
关键词： Sulfide ion conductivity,Nanofibre gel electrolyte,Efficiency enhancement,Quantum dot sensitized solar cells,Quantum dot doped electrolyte
更新于2025-09-23 15:21:01
-
Optimization and performance analysis of a solar concentrated photovoltaic-thermoelectric (CPV-TE) hybrid system
摘要： This work presents, for the first time, a statistical model to forecast the electrical efficiency of concentrated photovoltaic-thermoelectric system (CPV-TE). The main objective of this work is to analyze the impact of the input factors (product of solar radiation and optical concentration, external load resistance, leg height of TE and ambient temperature) most affecting the electrical efficiency of CPV-TE system. An innovative and integrated approach based on a multi-physics numerical model coupling radiative, conductive and convective heat transfers Seebeck and photoelectrical conversion physical phenomena inside the CPV-TE collector and a response surface methodology (RSM) model was developed. COMSOL 5.4 Multiphysics software is used to perform the three-dimensional numerical study based on finite element method. Furthermore, results from the numerical model is then analysed using the statistical tool, response surface methodology. The analysis of variance (ANOVA) is conducted to develop the quadratic regression model and examine the statistical significance of each input factor. The results reveal that the obtained determination coefficient for electrical efficiency is 0.9945. An excellent fitting is achieved between forecast values obtained from the statistical model and the numerical data provided by the three-dimensional numerical model. The influence of the parameters in order of importance on the electrical efficiency are respectively: product of solar radiation and optical concentration, the height legs of TE, external electrical resistance load, and ambient temperature. A simple polynomial statistical model is created in this work to predict and maximize the electrical efficiency from the solar CPV-TE system based on the four investigated input parameters. The maximum electrical efficiency of the proposed CPVTE (17.448%) is obtained for optimum operating parameters at 229.698 W/m2 value of product of solar radiation and optical concentration, 303.353 K value of ambient temperature, 2.681Ω value of resistance electrical load and at 3.083 mm value of height of TE module.
关键词： Concentrated photovoltaic-thermoelectric system (CPV-TE),Electrical efficiency enhancement,Response surface methodology (RSM)
更新于2025-09-19 17:13:59
-
Efficiency Enhancement of Perovskite CsPbBr <sub/>3</sub> Quantum Dot Light-emitting Diodes by Doped Hole Transport Layer
摘要： Balanced charge injection is essential to high-performance Perovskite CsPbBr3 quantum dot-based light-emitting diodes (QLEDs). However, low mobility of hole-transport materials (HTMs) severely restrict improving performance of QLEDs. Herein, we provide a novel HTMs to improve the highest occupied molecular orbital (HOMO) energy level structure and carrier mobility by doping poly (9-vinlycarbazole) (PVK) and poly [N, N′-bis(4-butylphenyl)-N, N′-bis(phenyl) benzi-dine] (poly-TPD). We also introduce poly (methyl methacrylate) (PMMA) as electron block layer to further achieve charge injection balance. Finally, an enhanced external quantum efficiency (EQE) of 0.53% and 414.83 cd/m2 was obtained. Compared with the untreated QLED, this result has been 8-fold enhanced, provides a new approach to attain better performance.
关键词： Quantum Dot Light-emitting Diodes,Efficiency Enhancement,Perovskite CsPbBr3,Hole Transport Layer
更新于2025-09-19 17:13:59
-
Efficiency Enhancement of Dye-Sensitized Solar Cells Using Tia??Nb Alloy Photoanodes with Mesoporous Oxide Surface
摘要： A native mesoporous titanium-niobium oxides layer on a Ti-6wt%Nb alloy sheet surface prepared through H2O2 pretreatment was successfully developed as an ef?cient photoanode for a dye-sensitized cell (DCCS). This alloyed mesoporous structure not only provided an increased surface area in contact with screen-printed TiO2 nanoparticles but also enabled Nb alloying in sintered nanoparticle deposits. Improvement of energy conversion ef?ciency of DSSCs can be increased up to 22% using H2O2 pretreatments with a proper post-annealing, and the mesoporous Ti–Nb photoanodes enhanced conversion ef?ciency by 15.2% to 18.3%, compared with unalloyed structures. EIS results under dark current indicate that DSSCs with mesoporous Ti–Nb photoanode exhibited a greater inhibition of recombination of electrons and holes at the interfaces of Nb-doped TiO2/dye/electrolyte layer due to energy barriers.
关键词： Efficiency enhancement,Mesoporous oxide surface,Ti–Nb alloy,Photoanodes,Dye-sensitized solar cells
更新于2025-09-19 17:13:59
-
[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Regime of Multi-Stage Trapping in Free Electron Lasers
摘要： Novel schemes of a trapping regime in FELs were studied. Proof-of-principle experiments on realization of “non-resonant” trapping were performed at Ka-band. For short-wavelength FELs we describe two different ways of the use of regime of “multi-stage” trapping. First, this regime can be a way for efficiency enhancement of FELs operating in SASE regime. Second, multi-stage amplification of a single-frequency RF signal can lead to an effective cooling of the operating electron beam.
关键词： electron beam cooling,multi-stage trapping,efficiency enhancement,non-resonant trapping,FELs
更新于2025-09-16 10:30:52
-
Recent Developments in Efficiency Enhancement of Non-Concentrating Photovoltaic Systems by Thermal Methods
摘要： Two different methods for reducing the operating temperatures of non-concentrating photovoltaic panels are analyzed and the performances are compared. Forced air cooling using a low power fan and use of a thermo siphon heat pipe are the modifications proposed for the purpose of efficiency enhancement. Experimental results of the two techniques are compared. It was found that, using a specific flow rate and selection of the proper heat pipe fluid and its operating conditions could help to reduce panel temperature considerably.
关键词： Temperature effects,Panel cooling,Photovoltaic,Efficiency enhancement
更新于2025-09-16 10:30:52
-
AIP Conference Proceedings [AIP Publishing INTERNATIONAL CONFERENCE ON INVENTIVE MATERIAL SCIENCE APPLICATIONS : ICIMA 2019 - Coimbatore, India (25–26 September 2019)] INTERNATIONAL CONFERENCE ON INVENTIVE MATERIAL SCIENCE APPLICATIONS : ICIMA 2019 - 2-D hollow core photonic crystal fiber-type absorption layer for enhancement of efficiency and broad response in multi-junction solar cell
摘要： We present a numerical based approach to design a new 2-D hollow core photonic crystal (2-D HCPC) structure of hexagonal lattice arrangement with circular air holes on an Indium Tin Oxide (ITO) slab. We used this structure as an anti-re?ective coating (ARC) layer on top of a multi-junction (GaP/InP/Si) solar cell. Apart from the ARC layer a GaAs PhC as back re?ector (BR) is used in the MJSC structure. A unique approach by blending light trapping structures to enhance solar cell e?ciency and light harvesting capabilities for wavelength beyond 750 nm is the goal of the present work. Under AM1.5G condition, the simulation results of the 2-D HC-PC structure as an absorption layer when incorporated on the MJSC structure led to an improvement of 6.38% in cell e?ciency over the previously reported by the conventional/non-photonic MJSC structure. The absorption spectral response using the 2-D HCPC pattern on ITO as ARC on the MJSC is achieved beyond 1000 nm. An optimization study is also carried out by using InAs as core of the 2-D HCPC structure which resulted to an enhancement of cell e?ciency by 9.34% as compared to the conventional/non-photonic MJSC structure.
关键词： efficiency enhancement,2-D hollow core photonic crystal,anti-re?ective coating,multi-junction solar cell,light trapping
更新于2025-09-12 10:27:22
-
Experimental study of active phase change cooling technique based on porous media for photovoltaic thermal management and efficiency enhancement
摘要： The photoelectric conversion efficiency of solar cells was significantly influenced by its operating temperature which promotes the studies in thermal management for photovoltaic (PV). This paper introduced a novel cooling method based on porous media applied in PV panel for thermal management and efficiency enhancement. An active phase change (APC) cooling system has been designed and fabricated to explore the possibility of cooling the PV panel, and ethanol was considered as the working fluid. By laboratory test, average temperature, temperature distribution, electrical performance of the PV panel as well as energy and exergy efficiency were analyzed in detail. The results demonstrated that the average temperature of the PV panel can be better managed by the APC cooling method compared with the uncooled conditions at different irradiation levels. Besides, increasing the non-condensable gas flow rates has a positive effect on the temperature reduction and maximum generated power of the PV panel. The obtained three-dimensional temperature distribution map proved that the temperature distribution was well uniform with the maximum temperature difference less than 5 °C. The maximum specific power improvement and percentage improvement in power generation were 21.37 W/m2 and 19.32%, respectively.
关键词： Photovoltaic,Efficiency enhancement,Active phase change,Thermal management,Porous media
更新于2025-09-12 10:27:22
-
Inside or outside: Evaluation of the efficiency enhancement of OLEDs with applied external scattering layers
摘要： Improving the efficiency of organic light-emitting diodes (OLEDs) by enhancing light outcoupling is common practise and remains relevant as not all optical losses can be avoided. Especially, externally attached scattering layers combine several advantages. They can significantly increase the performance and neither compromise the electric operation nor add high costs during fabrication. Efficiency evaluations of external scattering layers are often done with lab scale OLEDs. In this work we therefore study different characterization techniques of red, green and blue lab scale OLEDs with attached light scattering foils comprising TiO2 particles. Although we observe an increased external quantum efficiency (EQE) with scattering foils, our analysis indicates that areas outside the active area have a significant contribution. This demonstrates that caution is required when efficiency conclusions are transferred to large area applications, for which effects that scale with the edges become less significant. We propose to investigate brightness profiles additionally to a standard EQE characterizations as latter only work if the lateral scattering length is much smaller than the width of the active area of the OLED. Our results are important to achieve more reliable predictions as well as a higher degree of comparability between different research groups in future.
关键词： external scattering layers,efficiency enhancement,OLEDs,EQE,light outcoupling
更新于2025-09-12 10:27:22
-
Total Reflection Metasurface with Pure Modulated Signal
摘要： Metasurface has been proposed as one critical platform for orbital angular momentum (OAM) multiplexing. While metasurfaces have unique advantages to achieve light modulation with an ultrathin 2D layer, the relatively low transfer efficiency is a primary drawback. Such weakness leads to the mixing of unmodulated light into the output signal and greatly limits the functionality. A new design strategy is presented to fabricate self-filtering metasurface with pure signal light, which is computationally and experimentally verified on different applications, and it is also insensitive to the incident light polarization. Normal metasurface system requires bulky polarizer and filter, while our ultrathin design paves the way to multifunctional metasurface-based chip-scale circuits to replace the conventional bulky optical components. A proof-of-principle meta-cavity is designed to improve the transfer efficiency by 83%, while theoretical calculation shows 633% enhancement for an upgraded setup. This design can be widely applied to OAM optics, integrated photonics, optical sensing, data processing, and nanoimaging.
关键词： noise reduction,metasurfaces,nanophotonics,efficiency enhancement
更新于2025-09-04 15:30:14