- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - High-Efficiency Corrugated Monocrystalline Silicon Solar Cells with Multi-Directional Flexing Capabilities
摘要： High efficiency, lightweight and low cost flexible solar cells have attracted a growing interest in the last decades due to their increased applications. Here, we show high-efficiency (19%) and large scale (5 × 5 inch wafer) monocrystalline silicon solar cells with multi-directional flexing capabilities. The flexing of rigid solar cells with interdigitated back contacts is achieved using a photolithography-less corrugation technique. Results show that linear patterns enable flexibility in one direction with a minimum bending radius of 5 mm while diamond patterns result in multi-directional flexibility with different minimum bending radii and robust electrical performance.
关键词： monocrystalline silicon,multi-directional flexing,flexible solar cells,corrugation technique,high efficiency
更新于2025-09-23 15:19:57
-
Metastable Behavior on Cesium Fluoridea??Treated Cu(In <sub/> 1a?? <i>x</i> </sub> ,Ga <sub/><i>x</i> </sub> )Se <sub/>2</sub> Solar Cells
摘要： Metastable behavior of cesium fluoride (CsF)-treated Cu(In1–x,Gax)Se2 (CIGS) solar cells is investigated under heat-light soaking (HLS) and heat-soaking (HS) treatments. HLS increases open-circuit voltage, fill factor, efficiency, and net carrier concentration and decreases short-circuit current density, whereas heat-soaking treatment acts oppositely. The performance of a CsF postdeposition treatment to CIGS thin film in selenium vapor, and closer to stoichiometry copper content, did not mitigate the open-circuit voltage improvement after HLS. These results argue the traditional concept of the VSe–VCu divacancy complex for the total beneficial effect of HLS in alkali-treated CIGS solar cells. The metastable behavior observed in the CsF-treated devices due to the HLS and HS treatments is explained by the specific behavior of alkali-containing new compounds at the surface and/or the migration of alkali metals at the surface and bulk regions.
关键词： heat soaking,heat-light soaking,metastable behavior,high efficiency,CsF-postdeposition treatment
更新于2025-09-23 15:19:57
-
New carbazole-based bipolar hosts for efficient green phosphorescent organic light-emitting diodes
摘要： In this work, two new bipolar host materials 3-(5-(9H-carbazol-9-yl)-4’-(1-phenyl-1H-benzo[d]imidazole-2-yl)-[1,1’-biphenyl]-2-yl)-9-phenyl-9H-carbazole (BCZ-PBM) and 3-(5-(9H-carbazol-9-yl)-3’-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1’-biphenyl]-2-yl)-9-phenyl-9H-carbazole (BCZ-TRZ) were designed and synthesized by introducing benzimidazole and triazine groups as acceptor units with carbazole as the donor unit. These two compounds have excellent thermal stability with a high glass transition temperature (Tg > 160°C) and thermal decomposition temperature (Td > 450°C). Green phosphorescent organic light-emitting devices (PHOLEDs) D1 and D2 were obtained by doping Ir(ppy)3 into BCZ-PBM and BCZ-TRZ, in which BCZ-PBM based device D1 revealed better performance with an external quantum efficiency (EQE) of 20.4%, maximum current efficiency (CE) of 69.3 cd/A, and maximum power efficiency (PE) of 54.8 lm/W. Notably, the BCZ-PBM-based device exhibited excellent efficacy stability and a low efficiency roll-off of 1.7% at 1000 cd/m2 and 4.7% at 5000 cd/m2.
关键词： Carbazole,Green PHOLEDs,High efficiency,Bipolar host materials
更新于2025-09-23 15:19:57
-
The impact of interstitial Fe contamination on n-type Cz-Silicon for high efficiency solar cells
摘要： In this work, we have investigated the impact of interstitial Fe contamination on the effective minority carrier lifetime of n-type Cz silicon bulk material for high efficiency solar cells. The study covers a Fe concentration in the silicon bulk from 3.5 ? 1012 cm-3 to 2.7 ? 1014cm-3. We have added 5 different concentrations (30, 100, 300, 1000 and 3000 ppb) of Fe intentionally to a wet chemical process tank and measured the transfer to the silicon wafer surface mimicking a possible contamination during wet chemical processing. In order to fabricate carrier lifetime test vehicles, the silicon wafer is then passivated with thermal silicon oxide from both sides. The surface contamination is driven into the bulk by mimicking a high temperature process during solar cell manufacturing. Effective minority carrier lifetime is measured at injection levels from 1 ? 1013 cm-3 to 3 ? 1015cm-3. We have fitted the theoretical curve for interstitial Fe derived from the SRH theory to the measured values and extracted the Fe contamination concentration. This value is comparable to the calculated value extracted from the surface contamination measurement. For low level injection (LLI), we extracted the capture cross section for interstitial Fe to be 6.45 ? 10-17 cm/s ? 2.23 ? 10-17 cm/s. The measured Fe contamination levels are used for the conversion efficiency fitting of a n-type bifacial silicon solar cell using QUOKKA simulations. The simulations show that very low Fe contamination concentrations of [Fe]bulk ? 3.5 ? 1012 cm-3 ([Fe]surf ? 6 ? 1010cm-2) already degrade the solar cell efficiency by 10% relative.
关键词： Effective minority carrier lifetime,Interstitial Fe Contamination,QUOKKA simulations,n-type Si Solar cell,High efficiency
更新于2025-09-23 15:19:57
-
Dealing with Climate Parameters in the Fabrication of Perovskite Solar Cells under Ambient Conditions
摘要： Although perovskite solar cells have demonstrated impressive efficiencies in research laboratories (above 25%), there is a need for experimental procedures to fabricate solar cells under ambient conditions to substantially decrease manufacturing costs. Nevertheless, to achieve efficient and highly stable devices in these conditions, the moisture level in the atmosphere must be monitored. The relative humidity (RH) has classically been the parameter of choice; however, in this work we show that the parameter of relevance is the absolute content of water measured in the form of partial water vapour pressure (WVP). To highlight the importance of this parameter, we demonstrate that small changes in ambient temperature at the same RH result in huge changes in solar cell performance. This is due to the non-linear dependence of the WVP on temperature (according to the Clausius-Clapeyron equation), and explains the dispersion of results found in the literature for devices nominally made at the same ambient RH levels. To illustrate this critical effect, we have deposited MAPbI3 perovskite films at different WVP values, which were derived from the climate parameters, RH and laboratory temperature, present during fabrication (not controlled). Hence, we adapt the fabrication method to the ambient conditions by monitoring the WVP, which allows for the fabrication of MAPbI3 based devices with efficiencies of up to 18.2% outside the glove box. In fact, we have extended the procedure to accomplish high-efficiency FA0.83MA0.17PbI3 devices under ambient conditions by adjusting the DMSO proportion in the perovskite precursor solution to the WVP.
关键词： Water Vapor Pressure,High Efficiency,Perovskite solar cells,Clausius-Clapeyron equation,Ambient Conditions
更新于2025-09-23 15:19:57
-
Switchable, widely tunable and Interval-Adjustable multi-wavelength erbium-doped fiber laser based on cascaded filters
摘要： The High Efficiency Video Coding (HEVC) standard (ITU-T H.265 and ISO/IEC 23008-2) has been developed with the main goal of providing significantly improved video compression compared with its predecessors. In order to evaluate this goal, verification tests were conducted by the Joint Collaborative Team on Video Coding of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29. This paper presents the subjective and objective results of a verification test in which the performance of the new standard is compared with its highly successful predecessor, the Advanced Video Coding (AVC) video compression standard (ITU-T H.264 and ISO/IEC 14496-10). The test used video sequences with resolutions ranging from 480p up to ultra-high definition, encoded at various quality levels using the HEVC Main profile and the AVC High profile. In order to provide a clear evaluation, this paper also discusses various aspects for the analysis of the test results. The tests showed that bit rate savings of 59% on average can be achieved by HEVC for the same perceived video quality, which is higher than a bit rate saving of 44% demonstrated with the PSNR objective quality metric. However, it has been shown that the bit rates required to achieve good quality of compressed content, as well as the bit rate savings relative to AVC, are highly dependent on the characteristics of the tested content.
关键词： standards,MPEG-H Part 2,Moving Picture Experts Group (MPEG),Video Coding Experts Group (VCEG),High Efficiency Video Coding (HEVC),H.265,Advanced Video Coding (AVC),Joint Collaborative Team on Video Coding (JCT-VC),video compression
更新于2025-09-23 15:19:57
-
Bicarbazole-based oxalates as photoinitiating systems for photopolymerization under UV-Vis LEDs
摘要： Photoinitiators are critical to initiate chain reactions in photopolymerization. For such applications, the absorption of photoinitiator must be compatible with the emission of light sources and enables the fast manufacturing of three-dimensional network or structures. Light-emitting diode (LED) is a new kind of energy-saving and environmental protection light source, exhibiting a substantial response in the near UV and visible range to replace the traditional mercury lamp and other light sources in photopolymerization. Here, we introduce methyl oxalate into bicarbazole chromophore (BiCz). By variation of the single or double substituents in the BiCz, we demonstrate that the absorption spectra can be adjusted and redshift to visible range and show good absorption in the near UV and visible range (365–475 nm). We explore their photochemistry based on experimental results and theoretical calculations and the mechanism of photoreactions have been verified. The super photostability by themselves and good hydrogen abstraction ability from amine co-initiator make them as excellent near UV and visible light active photoinitiators. Critically, the photoinitiation of the free-radical polymerization of acrylate monomers with low content (0.1% concentration) upon LED irradiation at 365–475 nm, exhibits excellent application potential in light curing and other fields.
关键词： free-radical polymerization,high efficiency,photoinitiators,UV–visible LEDs
更新于2025-09-23 15:19:57
-
[IEEE 2019 24th Microoptics Conference (MOC) - Toyama, Japan (2019.11.17-2019.11.20)] 2019 24th Microoptics Conference (MOC) - Simultaneous Cross-Sectional Velocity Distribution Measurements Using Laser Doppler Velocimeter Employing 7 ?? 8 Spatial Encoding
摘要： The High Efficiency Video Coding (HEVC) standard (ITU-T H.265 and ISO/IEC 23008-2) has been developed with the main goal of providing significantly improved video compression compared with its predecessors. In order to evaluate this goal, verification tests were conducted by the Joint Collaborative Team on Video Coding of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29. This paper presents the subjective and objective results of a verification test in which the performance of the new standard is compared with its highly successful predecessor, the Advanced Video Coding (AVC) video compression standard (ITU-T H.264 and ISO/IEC 14496-10). The test used video sequences with resolutions ranging from 480p up to ultra-high definition, encoded at various quality levels using the HEVC Main profile and the AVC High profile. In order to provide a clear evaluation, this paper also discusses various aspects for the analysis of the test results. The tests showed that bit rate savings of 59% on average can be achieved by HEVC for the same perceived video quality, which is higher than a bit rate saving of 44% demonstrated with the PSNR objective quality metric. However, it has been shown that the bit rates required to achieve good quality of compressed content, as well as the bit rate savings relative to AVC, are highly dependent on the characteristics of the tested content.
关键词： standards,MPEG-H Part 2,Moving Picture Experts Group (MPEG),Video Coding Experts Group (VCEG),High Efficiency Video Coding (HEVC),H.265,Advanced Video Coding (AVC),Joint Collaborative Team on Video Coding (JCT-VC),video compression
更新于2025-09-23 15:19:57
-
Over 14% Efficiency Folding-Flexible ITO-free Organic Solar Cells Enabled by Eco-friendly Acid-Processed Electrodes
摘要： Environment-friendly manufacturing and mechanical robustness are imperative for commercialization of flexible OSCs as green-energy source, especially in portable and wearable self-powered flexible electronics. Although, the commonly adopted PEDOT:PSS electrodes that are treated with severely corrosive and harmful acid lack foldability. Herein, efficient folding-flexible OSCs with highly conductive and foldable PEDOT:PSS electrodes processed with eco-friendly cost-effective acid and polyhydroxy compound are demonstrated. The acid treatment endows PEDOT:PSS electrodes with high conductivity. Meanwhile, polyhydroxy compound doping contributes to excellent bending flexibility and foldability due to the better film adhesion between PEDOT:PSS and PET substrate. Accordingly, folding-flexible OSCs with high efficiency of 14.17% were achieved. After 1,000 bending or folding cycles, the device retained over 90% or 80% of its initial efficiency, respectively. These results represent one of the best performances for ITO-free flexible OSC reported so far and demonstrate a novel approach toward commercialized efficient and foldable green-processed OSCs.
关键词： high efficiency,flexible organic solar cells,foldability,PEDOT:PSS,eco-friendly acid
更新于2025-09-23 15:19:57
-
A perspective on blue TADF materials based on carbazole-benzonitrile derivatives for efficient and stable OLEDs
摘要： The advent of materials with thermally activated delayed ?uorescence (TADF) has triggered a wave of research to break the mutual exclusion of high ef?ciency and long lifetime of blue organic light-emitting diodes. Representatively, multiple donor-acceptor-type carbazole-benzonitrile (CzBN) derivatives have realized the longest device lifetimes in the blue region up to now together with high ef?ciencies among all TADF emitters. This perspective timely summarizes the progress of molecular design and device performances of CzBN derivatives and is concluded by providing suggestions on the future development of such materials and the corresponding devices.
关键词： OLEDs,high efficiency,carbazole-benzonitrile derivatives,long lifetime,blue TADF materials
更新于2025-09-23 15:19:57