共查询到20条相似文献，搜索用时 0 毫秒
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Giovanni Pica;Riccardo Montecucco;Andrea Zanetta;Aleksandra Oranskaia;Fabiola Faini;Lorenzo Pancini;Nada Mrkyvkova;Peter Siffalovic;Pia Dally;Valentina Pirota;Martin Ledinsky;Michele De Bastiani;Stefaan De Wolf;Filippo Doria;Udo Schwingenschlögl;Giulia Grancini; 《Solar RRL》2024,8(9):2300681
Defect passivation is nowadays considered a must-have route for high-efficiency perovskite solar cells. However, a general rule that correlates the choice of passivating agents with performance enhancements is still missing. Herein, two different thiophene salts that are used as passivating agents are compared, namely thiophene methylammonium chloride and thiophene ethylammonium chloride (TEACl), which are used for the passivation of bulk and surface defects in triple-cation-based metal halide perovskites. First, it is observed that the surface passivation method leads to better device performances reaching a power conversion efficiency of 23.56%, with reduced voltage losses and increased fill factor when compared with the reference. Second, it is demonstrated that the chemical structure of the cation dictates its capability either in passivating bulk defects effectively or to form a superficial two-dimensional/three-dimensional heterostructure, which happens only for the TEACl case. The chemical composition and the cation dimension are responsible for device performance enhancement as observed by a joint spectroscopic and density functional theory simulations study, providing rational guidelines for further smart device design. 相似文献
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One of the main problems that limit the extensive use of photovoltaic (PV) systems is the increase in the temperature of PV panels. Overheating of a PV module decreases the performance of the output power by 0.4% to 0.5% per 1°C over its rated temperature that in most cases is 25°C. An effective way of improving electrical performance (power output and efficiency) and reducing the rate of thermal degradation of a PV module is to reduce the operating temperature of the PV surface by a cooling medium. To achieve this, nanofluids can be considered as a potentially effective solution for cooling. In this study, two types of nanofluids, namely Al2O3 and TiO2 water‐based mixture of different volume flow rates and concentrations (0.01%, 0.05%, and 0.1%) by weight, were used. Also, three PV panels were cooled simultaneously using nanofluids, water, and natural air, respectively. Results showed that nanofluids for cooling enhanced heat transfer rate much better than water and natural air. Best results were achieved for TiO2 nanofluids at the considered concentration (0.1 wt%). Nanofluid cooling of turbulent flows for such an application has not been investigated before. These results represent the first application of nanofluid cooling in the turbulent flow regimes and in outdoor conditions including real solar irradiation. 相似文献
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A. Sivakumar R. Sathiyamoorthi N. Alagumurthi V. Jayaseelan K. Sudhakar 《亚洲传热研究》2021,50(4):3094-3118
This study aims to evaluate the thermal performance and friction factor characteristics of the U-shaped serpentine microchannel heat sink using three different nanofluids. Two distinct nanoparticles, namely Al2O3 (alumina) and CuO (copper oxide), were used for the preparation of nanofluids using water and ethylene glycol (EG) as base fluids. Three nanofluids, namely nanofluid I (Al2O3 + water), nanofluid II (CuO + water), and nanofluid III (CuO + EG), have been prepared. The results showed that the thermal conductivity of nanofluids was increased for all concentrations (from 0.01 to 0.3%), compared with base fluids. The theoretical values derived from the relationship between the Darcy friction factor showed a clear understanding of the fully developed laminar flow. Thermal resistance for nanofluid III was lower than other nanofluids, resulting in a higher cooling efficiency. The nanofluid mechanism and the geometry of the U-shaped serpentine heat sink have led to the improvement in the thermal performance of electronic cooling systems. 相似文献
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Žan Ajdič;Marko Jošt;Marko Topič; 《Solar RRL》2024,8(12):2400247
Improving the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) remain the two most important goals of perovskite research. Herein, the effects of Al2O3 interlayer on the performance of formamidinium-cesiums and “triple cation” PSCs by depositing a thin Al2O3 layer via atomic layer deposition on different interfaces are analyzed. It is found that it can efficiently serve as a passivation layer of perovskite absorber, as a seed layer for the compact growth of the subsequent SnO2 layer, or as a capping layer to the whole cell in the superstrate configuration to prevent moisture ingress. The optimized devices utilizing Al2O3 have on average more than 1% absolute higher PCE, with reduced penetration of moisture inside the device. Especially, the capping layer has shown the greatest benefit, extending the stability of the devices by more than two times and allowing long-term operation without encapsulation. In the best case, a T80 time of almost 900 h under day/night-cycling illumination is obtained. The observed trends are based on data from a large number of devices (more than 300 devices were tested in the maximum power point), which give statistical relevance to the promising results. 相似文献
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研究以并流共沉淀法制备Cu/La2 O3 /Al2 O3 系列催化剂催化甲醇水蒸气重整制氢反应过程 ,考察了La2 O3含量、反应温度、水醇比、液体空速 (WHSV)等因素对催化剂活性的影响。结果表明 :催化剂表现出较好的低温活性、高氢气选择性和稳定性。La2 O3 质量分数为 15 % ,在 2 5 0℃反应时 ,催化剂活性表现最佳 ,甲醇摩尔转化率为94 .5 % ,氢气选择性为 10 0 % ,CO摩尔分数为 1.0 5× 10 -7。 相似文献
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Mahmoud Algazzar 《国际可持续能源杂志》2016,35(3):217-229
In this research, n-dodecylthiol was added to poly(3-hexylthiophene)/[6,6]-phenyl-C71-butyric acid methyl ester (P3HT/PC70BM) polymer solar cells to improve the crystallinity of P3HT and enhance the phase separation of P3HT/PC70BM. UV–Vis and external quantum efficiency results showed enhancement in P3HT self-organisation ability which led to improved crystallinity and intensified phase separation of P3HT/PC70BM in the cast films. Atomic force microscopic analysis showed that adding n-dodecylthiol to P3HT/PC70BM resulted in an increase in surface roughness which provided more space for P3HT crystallites to form. X-ray diffraction and differential scanning calorimetry analysis showed a higher crystallinity in the heat-treated samples containing up to 2% of n-dodecylthiol by volume, which resulted in a nearly 33% increase in device efficiency at the optimum annealing conditions of 150°C for 30 min. The cell performance deteriorated abruptly at temperatures higher than 150°C. 相似文献
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M.D. Barankin E. Gonzalez II A.M. Ladwig R.F. Hicks 《Solar Energy Materials & Solar Cells》2007,91(10):924-930
The plasma-enhanced chemical vapor deposition of aluminum-doped zinc oxide has been demonstrated for the first time at 800 Torr and under 250 °C. A film resistivity of and a transparency of 95% from 375 to 2500 nm was obtained for deposition at 20-mTorr diethylzinc, 1.0 Torr CO2, 799 Torr He, a TMAl/DEZn ratio of 1:100, RF power, and 225 °C. The average aluminum concentration in the ZnO film was . It was found that, while the growth rate did not change with substrate temperature, both the resistivity and optical absorption coefficient declined with increasing temperature. 相似文献
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Gabriel Bartholazzi;Mohamed M. Shehata;Rabin Basnet;Christian Samundsett;Daniel H. Macdonald;Lachlan E. Black; 《Solar RRL》2024,8(2):2300727
Passivating contacts based on transition metal oxides are of great interest for applications in crystalline silicon (c-Si) solar cells due to their improved optical transparency and potential cost reduction. In this work, the contact resistivity and passivation for thermally evaporated Cu2O are investigated and optimized, with and without an Al2O3 interlayer, as a hole-selective contact to c-Si. Additionally, we implement an AlyTiOx/TiO2 stack as a novel passivating tunnel interlayer for hole-selective contacts, achieving an implied open-circuit voltage iVoc of 630 mV and a record-low J0 of 212 fA cm−2 while maintaining a contact resistivity ρc of 62 mΩ cm2. A record-low ρc of 8 mΩ cm2 for Cu2O-based contacts is also demonstrated at the expense of passivation. The addition of the interlayer resulted in a 2% absolute improvement in the efficiency of proof-of-concept c-Si cells with full-area rear Cu2O contacts, reaching 19.1%.The demonstration of this novel interlayer stack provides new avenues to improve the performance also of other hole-selective passivating contacts. 相似文献
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以生物质气化模拟合成气H2/CO/N2为原料气,以堇青石蜂窝陶瓷为基体制备Ni/Al2O3整体式催化剂,通过扫描电镜(SEM)、比表面积(BET)、X射线衍射(XRD)、程序升温反应法(TPR)、热重分析(TG)等表征分析手段,考察催化剂制备方法(浸渍法和溶胶-凝胶法)、温度(250~550℃)及空速GHSV(6000~14000 mL/(g·h))对催化剂甲烷化性能的影响。结果表明:浸渍法制备的Ni/Al2O3催化剂(DIP-Ni/Al2O3)与溶胶-凝胶法制备的Ni/Al2O3催化剂(SGNi/Al2O3)相比,前者甲烷化性能较好。在H2、CO、N2物质的量之比为3∶1∶1且空速为10000 mL/(g·h)条件下,浸渍法制备的Ni/Al2O3催化剂在400℃时甲烷化性能最佳,且该条件下CO转化率为98.6%,CH4选择性为90.9%。当H2、CO、N2物质的量之比为3∶1∶1且温度为400℃时,在实验空速范围内,浸渍法制备的Ni/Al2O3催化剂CO转化率和CH4选择性均基本稳定在90%,甲烷化性能较好。 相似文献
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聚光型太阳能光伏光热系统(CPV/T)在传统光伏发电系统的基础上增加了聚光系统和光热系统,在通过聚光系统提高光伏效率的同时将系统中多余的热量加以利用,以达到太阳能最大化利用的目的。本文介绍了CPV/T系统的工作原理及其能效影响因素,以直接影响系统太阳能综合利用效率的聚光器技术、光伏电池技术和光伏冷却技术作为分析对象,结合近几年国内外最新研究成果比较了不同类型聚光器、光伏电池以及冷却方式的优劣,列举了常见的光伏余热利用方式。分析认为:CPV/T系统虽然具有更高的太阳能利用率,但应加大对系统尤其是聚光器经济性的分析;考虑在系统中应用叠层光伏电池缓解聚光器带来的系统体积过大问题;新电池开发过程中应更注意光伏电池的温度系数以减少冷却系统的压力,冷却技术在强化散热的同时也应注意热量的收集方法及其与利用途径的有效结合。 相似文献
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量子点敏化纳米TiO2太阳电池（QDSSCs）因成本低廉,近年来得到广泛关注。但是其光电转换效率仍然较低,其中主要的原因是量子点表面缺陷密度高,表面与界面电子复合严重。本文以Al2O3为纳米TiO2/CdSe QDs的界面修饰层,采用暗态下的电化学阻抗谱（EIS）以及开路电压衰减谱考察了Al2O3对抑制电子复合所起的作用,并简析了其中的作用机理。研究结果表明,TiO2表面修饰Al2O3后,其导带边上移;此外,TiO2/QDs界面缺陷态降低,界面电子复合降低,使器件的短路电流、开路电压以及填充因子提高,光电转换性能得到改善。 相似文献
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建立了采用抛物面槽聚焦集热器(PTC)的太阳能双效LiBr/H_2O吸收式制冷系统的理论模型,对其性能进行了数值模拟,研究了运行温度对系统总效率的影响,计算结果显示:PTC在高温工作条件下具有非常高的集热效率;运行温度为173.5℃时,系统总效率最高,达到0.8250;与采用复合抛物面聚焦集热器(CPC)和高效真空管集热器(ETC)相比,采用PTC的太阳能双效吸收式制冷系统具有最佳的系统性能;相同条件下,选用PTC时集热面积最小,但由于PTC的价格很高,导致系统成本很高。 相似文献
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Shin-ichi Muramatsu Tsuyoshi Uematsu Yasushi Nagata Hiroyuki Ohtsuka Terunori Warabisako 《Solar Energy Materials & Solar Cells》1997,48(1-4)
Outstanding passivation properties for p-type crystalline silicon surfaces were obtained by using very thin n-type microcrystalline silicon (μc-Si) layers with a controlled interface structure. The n-type μc-Si layers were deposited by the RF PE-CVD method with an insertion of an ultra-thin oxide (UTO) layer or an n-type amorphous silicon (a-Si : H) interface layer. The effective surface recombination velocity (SRV) obtained was very small and comparable to that obtained using thermal oxides prepared at 1000°C. The structural studies by HRTEM and Raman measurements suggest that the presence of UTO produces a very thin a-Si : H layer under the μc-Si. A crystal lattice discontinuity caused by these interface layers is the key to a small SRV. 相似文献