修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

260 条数据
?? 中文(中国)
  • Recent Progress in Chlorinated Organic Photovoltaic Materials

    摘要: Over the past few years, the development of new materials has contributed to rapid increases in the power conversion efficiencies (PCEs) of organic photovoltaic (OPV) cells to over 17%, showing great potential for the commercialization of this technology in the near future. At this stage, designing new materials with superior performance and low cost simultaneously is of crucial importance. Chlorinated materials are emerging as new stars with very high PCEs, creating a molecular design trend to replace the most popular fluorinated materials. For example, by using chlorinated non-fullerene acceptors, we recently got a record PCE of 17% for single-junction OPV cells. Firmly based on recent advances, herein we focus on the topic of chlorinated OPV materials, aiming to provide a guideline for further molecular design.

    关键词: chlorinated materials,organic photovoltaic cells,power conversion efficiencies,non-fullerene acceptors,molecular design

    更新于2025-09-23 15:19:57

  • [IEEE 2019 7th International Youth Conference on Energy (IYCE) - Bled, Slovenia (2019.7.3-2019.7.6)] 2019 7th International Youth Conference on Energy (IYCE) - Retrofit of the Lighting System in Common Spaces of Buildings

    摘要: AC voltage regulation is required in both the domestic and industrial sectors to avoid undesired effects from random voltage variations of the power supply. The paper introduces an ac voltage stabilizer/converter (ACVS) that is based on a controllable autotransformer technology. The proposed ACVS offers a specified strategy of voltage regulation, less harmonics, and low cost. The paper explains the operating principle of the ACVS and derives its nonlinear mathematical model. To ensure the desired performance of the ACVS while it is subject to uncertain input voltage and load variations, an optimal control strategy is designed. It is achieved via transforming the ACVS model extending with fictive axis emulation into a rotating reference frame and the linearization of the model via specific orientation of the reference frame and introducing a linear control action. Operation of the ACVS is simulated under different disturbances due to load and grid voltage changes, and compared to voltage stabilization with application of I and PI controllers. Experimental results are presented to demonstrate the voltage regulation technology.

    关键词: electric variables control,power quality,AC–AC power conversion,linear-quadratic control,voltage control

    更新于2025-09-19 17:13:59

  • [IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - The Influence of the Excited State (ES) Lasing in Quantum Dot-in-a-Well (QDWELL) Structure on the QDWELL Laser Performance in Optical Communication Systems

    摘要: AC voltage regulation is required in both the domestic and industrial sectors to avoid undesired effects from random voltage variations of the power supply. The paper introduces an ac voltage stabilizer/converter (ACVS) that is based on a controllable autotransformer technology. The proposed ACVS offers a specified strategy of voltage regulation, less harmonics, and low cost. The paper explains the operating principle of the ACVS and derives its nonlinear mathematical model. To ensure the desired performance of the ACVS while it is subject to uncertain input voltage and load variations, an optimal control strategy is designed. It is achieved via transforming the ACVS model extending with fictive axis emulation into a rotating reference frame and the linearization of the model via specific orientation of the reference frame and introducing a linear control action. Operation of the ACVS is simulated under different disturbances due to load and grid voltage changes, and compared to voltage stabilization with application of I and PI controllers. Experimental results are presented to demonstrate the voltage regulation technology.

    关键词: AC–AC power conversion,electric variables control,linear-quadratic control,power quality,voltage control

    更新于2025-09-19 17:13:59

  • [IEEE IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - D.C., DC, USA (2018.10.21-2018.10.23)] IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - Steady-state equivalent circuit of LED bulbs accounting for the current harmonics

    摘要: Nowadays, the light-emitting diode (LED) bulb is one of the preferred choice in lighting system design. Electrical models of the LED lamps have to consider their nonlinear behavior involving current distortion on the mains. With this purpose, an equivalent electrical circuit emulating the current drawn by a LED Bulbs is carried out. In this work, different lamps have been tested under variable supply voltage. The comparison between the simulations performed by means of PSpice and the experimental measurements has highlighted that linear interpolation for the amplitude of each harmonic current, as function of the voltage on the main, provides a good estimation of the total current waveform.

    关键词: LED Bulbs,power conversion,LED lamps,Current harmonics,equivalent circuits,lighting,total harmonic distortion,power quality

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE Symposium on Product Compliance Engineering - Asia (ISPCE-CN) - Kowloon, Hong Kong (2019.10.23-2019.10.25)] 2019 IEEE Symposium on Product Compliance Engineering - Asia (ISPCE-CN) - Critical Study on the Relationship between Power Conversion Technique and Energy Efficiency on LED driver

    摘要: In this paper, a critical study on the improvement of energy efficiency on the commercial light emitting diode (LED) driver along with the development of power conversion technique over the last two decades was conducted. A new classification of LED driver was proposed based on the new technologies and construction invented recently, and the past classifications of LED driver used. The corresponding energy efficiency on different types of LED drivers was studied accordingly. A new effective labeling scheme of energy efficiency on LED driver that will be suitable in Hong Kong from 2019 to 2029 was proposed based on the recent situation and the new classification. This proposed labelling scheme can be used as reference by the manufacturers of LED driver on the selection of power conversion techniques with various levels of energy efficiency.

    关键词: energy efficiency,power conversion,LED driver

    更新于2025-09-19 17:13:59

  • The photon absorber and interconnecting layers in multijunction organic solar cell

    摘要: Organic photovoltaic devices have long been considered as an important alternative for coal-based energy technologies due to their low-cost, lightweight and flexible nature. However, the power conversion efficiencies of such cells are limited by thermalization and transmission losses, which can be overcome by stacking multiple cells in a tandem configuration. This approach allows utilization of the wider spectrum of solar light, helping in attaining the theoretical limits for single cell efficiency (~30%). However, the performance of such tandem organic solar cells depends largely on several factors, including the proper design of absorber, sub-cells and interconnecting layer materials. In this review, recent studies on the development of different fullerene, non-fullerene, small molecule acceptor based active layers have been reported. Also, some recent works in the field of the inorganic-organic hybrid tandem cells have been briefly discussed. The purpose of this review is manifold: to provide the readers with a comprehensive overview of past, current research, recent developments, and open problems of tandem organic solar cells.

    关键词: Power conversion efficiency,Tandem solar cell,Absorber materials,Interconnecting layer,Organic photovoltaics

    更新于2025-09-19 17:13:59

  • Effect of fluorine substituents on benzothiadiazole-based Da????a??Aa?2a????a??A photosensitizers for dye-sensitized solar cells

    摘要: Two D–π–A0–π–A organic dyes with triazatruxene (TAT) as the electron donor, thiophene as the π-spacer, benzoic acid as the anchor group, and benzothiadiazole (BT) or difluorobenzo[c][1,2,5]thiadiazole (DFBT) as the additional acceptor, namely LS101 and LS102, respectively, were applied to dye-sensitized solar cells (DSSCs). As fluorine substituents are usually strong electron-withdrawing groups, introducing two fluorine atoms into BT was expected to strengthen the electron-withdrawing ability of the auxiliary acceptor, resulting in DSSCs with a broader light capture region and further improved power conversion efficiency (PCE). Fluorine is the smallest electron-withdrawing group with an induction effect, but can also act as an electron-donating group owing to its conjugation effect. When the conjugation effect is dominant, the electron-withdrawing ability of additional acceptor DFBT decreases instead. Accordingly, the band gap of LS102 was broadened and the UV-vis absorption spectrum was blue-shifted. In the end, DSSCs based on LS101 achieved a champion PCE of 10.2% (Jsc = 15.1 mA cm?2, Voc = 966 mV, FF = 70.1%) while that based on LS102 gave a PCE of only 8.6% (Jsc = 13.4 mA cm?2, Voc = 934 mV, FF = 69.1%) under standard AM 1.5G solar irradiation (100 mW cm?2) with Co2+/Co3+ as the electrolyte.

    关键词: Power conversion efficiency,Fluorine substituents,Organic photosensitizers,Benzothiadiazole,Dye-sensitized solar cells

    更新于2025-09-19 17:13:59

  • Efficient and Photostable Ternary Organic Solar Cells with a Narrow Bandgap Non-Fullerene Acceptor and Fullerene Additive

    摘要: Recent breakthroughs in molecular design have allowed for remarkable achievement in the field of non-fullerene acceptor (NFA)-based organic solar cells (OSCs) with high power conversion efficiencies (PCEs) of over 15%. However, despite such promising advances, the inferior stability of OSCs under operational conditions remains a prominent challenge that must be overcome for their practical realization. Here, versatile ternary photoactive systems with simultaneously enhanced efficiency and photostability are developed by introducing a small amount of fullerene (PC71BM) into a narrow bandgap NFA-based bulk heterojunction nanocomposite (PTB7-Th:IEICO-4F); this approach leads to an enhanced PCE of 10.55% and a prolonged lifetime, retaining approximately 80% of the initial PCEs after 500 h of operation under continuous illumination. Based on the energy levels and surface energies of the component materials, cascade energetic alignment facilitates electron transfer without trapping. The PTB7-Th/PC71BM interface provides an energy barrier to suppress recombination between holes in PTB7-Th and electrons in IEICO-4F. Moreover, a small amount of PC71BM promotes favorable molecular packing and orientation of IEICO-4F, leading to enhanced electron mobility and balanced charge transport. The study on the transient absorption spectroscopy reveals that the ternary blend effectively suppresses the evolution of charge recombination.

    关键词: photostability,non-fullerene acceptor,power conversion efficiency,organic solar cells,ternary blend

    更新于2025-09-19 17:13:59

  • Efficient Modulation of End Groups for the Asymmetric Small Molecule Acceptors Enabling Organic Solar Cells with over 15% Efficiency

    摘要: Non-fullerene organic solar cells (OSCs) have attracted tremendous interest and made an impressive breakthrough, largely due to advances in high-performance small molecule acceptors (SMAs). The relationship between short-circuit current density (JSC) and open-circuit voltage (VOC) is usually shown as one falls and another rises. Controlling the trade-off between JSC and VOC to harvest high power conversion efficiencies (PCEs) still remains as a challenge. Herein, dithieno[3,2-b:2?,3?-d]pyrrole (DTP) based asymmetric SMAs with different chlorinated dicyanoindanone-based end groups, named TPIC, TPIC-2Cl and TPIC-4Cl, are designed and synthesized. These asymmetric acceptors exhibit remarkable red-shifted absorption profile, while energy levels are simultaneously down-shifted when the numbers of chlorine atoms alter from 0, 1 to 2, due to the gradually improved electronegativity. As a result, PM7: TPIC-4Cl based OSCs achieved a champion PCE of 15.31%, which is the highest PCEs for non-fullerene binary OSCs based on asymmetric SMAs. The superiority of PM7: TPIC-4Cl system consists of the balanced charge transport, favorable phase separation, efficient exciton dissociation and extraction, coupled with remarkable π–π stacking and crystallinity of the SMAs. Our results highlight the important strategy of asymmetric molecular design to optimize the trade-off between VOC and JSC, reaching a high PCE.

    关键词: asymmetric molecular design,small molecule acceptors,chlorinated dicyanoindanone-based end groups,Non-fullerene organic solar cells,power conversion efficiencies

    更新于2025-09-19 17:13:59

  • Synthesis of a new wide-bandgap conjugated copolymer with 3-trifluoromethylthiophene monomer and Its application to non-fullerene polymer solar cells

    摘要: In this study, a novel wide-bandgap conjugate donor-acceptor type copolymer, PBDT-TFMTh, containing benzodithiophene (BDT) as a donor unit and trifluoromethyl (TFM)-substituted thiophene (Th) as an acceptor unit was designed and synthesized. The physical, optical, and electrochemical properties of PBDT-TFMTh were studied in detail and it was found to have lower-lying highest occupied and lowest unoccupied molecular orbitals. The polymer solar cell with an active layer consisting of PBDT-TFMTh and acceptor IDT(TCV)2 showed a relatively high power conversion efficiency of 2.25% after thermal annealing at 120 (cid:1)C.

    关键词: power conversion efficiency,wide-bandgap copolymer,3-trifluoromethylthiophene,polymer solar cell

    更新于2025-09-19 17:13:59