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Life span and overall performance enhancement of Solar Photovoltaic cell using water as coolant: A recent review
摘要： In today’s world, as electricity consumption is increasing, people are more dependent on electricity. Solar Photovoltaic system is one method to generate electricity. The conversion efficiency of solar photovoltaic panel depends on atmospheric condition and reflection. The operating temperature of photovoltaic module plays an important role in performance of PV system as efficiency of PV system decreases when temperature module increases. The operating photovoltaic cells at high temperature degrades the material of it in long time. Operating solar photovoltaic at lower temperature will increase its lifespan. This will reduce module surface area by increasing overall output power. Researchers have proposed and tested several cooling techniques for the panel. One of the most common and effective way to cool PV module is used of water as coolant. In this paper, efforts made by various researchers to cool down solar photovoltaic module to increase the efficiency using water application have been discussed. The application of water on front surface, rear surface, both front and rear surface have been reviewed extensively. The performance of module by immersion in water also have been reported.
关键词： Nanofluids,Electrical conversion efficiency,Solar Photovoltaics,Thermal conductivity,Overall efficiency
更新于2025-09-12 10:27:22
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Near 5% DMSO is the best: A structural investigation of PEDOT: PSS thin films with strong emphasis on surface and interface for hybrid solar cell
摘要： Effect of dimethyl sulfoxide (DMSO) doping on poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) thin films have been optimized for obtaining better hole transport layer in hybrid solar cell. The correlation between morphology and conductivity is established through atomic force microscopy and transmission length method measurements. On the other hand, change in the shape of the building blocks (from spheroidal-like to ellipsoidal-like) in the PEDOT:PSS films with DMSO concentration is apparent from their electron density profiles and topographies, suggesting possible conformational change (from coil-like to rod-like) in film by X-ray reflectivity. Such change is further evident from their compositional profiles, work functions and electronic band structures estimated from X-ray and ultraviolet photoelectron spectroscopies. In fact, complementary information suggest that near 5% DMSO doped PEDOT:PSS film is governed through maximum in-plane extended ellipsoidal-like blocks as well as well organized in out-of-plane ordering which is likely to be the optimum structure for increased the highest electrical conductivity up to 1230 S/cm. Finally, maximum power conversion efficiency of 11 % with open-circuit voltages around 600 mV, a short-circuit current density higher than 30 mA/cm2 and a fill factor of 59.4% is achieved for the 5% DMSO doped PEDOT:PSS/n-Si hybrid solar cell, which is perfectly correlated with their structure.
关键词： Morphology,Conductivity,PEDOT:PSS,DMSO doping,Hybrid solar cell
更新于2025-09-11 14:15:04
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A sensitive photochemical reaction-capacitively coupled contactless conductivity detection system for HPLC and its application in determination of Cyclosporin A
摘要： High performance liquid chromatography (HPLC) post-column photochemical reaction (PR) coupled capacitively coupled contactless conductivity detector (C4D) was used for the first time in analysis of weak ultraviolet (UV)-absorbing, non-fluorescence and nonpolar compound. A series of conditions including the radiation power of light source, the length of the reaction tube and the thickness of detection tube were investigated. HPLC-PR-C4D system was successfully applied to the determination of Cyclosporin A (CsA). Consequently, under optimal conditions, the detection system exhibited a detection limit of 0.04 μg/mL and wide linear range from 0.5 μg/mL to 100 μg/mL for CsA detection. Application of the HPLC-PR- C4D system to pharmaceutical formulation and biological samples revealed the system developed maybe reliably applied to clinical studies.
关键词： Photochemical reaction,Cyclosporin A,HPLC,Capacitively coupled contactless conductivity detection,Application
更新于2025-09-11 14:15:04
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revealed by resonant photoelectron spectroscopy
摘要： Resonant photoelectron spectroscopy at the Co and Mn 2p core absorption edges of half-metallic Co2MnGe has been performed to determine the element-speci?c density of states (DOS). A signi?cant contribution of the Mn 3d partial DOS near the Fermi level (EF) was clari?ed by measurement at the Mn 2p absorption edge. Further analysis by ?rst-principles calculation revealed that it has t2g symmetry, which must be responsible for the electrical conductivity along the line perpendicular to the ?lm plane. The dominant normal Auger contribution observed at the Co 2p absorption edge indicates delocalization of photoexcited Co 3d electrons. The difference in the degrees of localization of the Mn 3d and Co 3d electrons in Co2MnGe is explained by the ?rst-principles calculation. Our ?ndings of the element-/orbital-speci?c electronic states near EF will pave the way for future interface design of magnetic tunneling junctions to overcome the temperature-induced reduction of the magnetoresistance.
关键词： first-principles calculation,magnetic tunneling junctions,normal Auger contribution,half-metallic Co2MnGe,magnetoresistance,Resonant photoelectron spectroscopy,Mn 3d partial DOS,element-speci?c density of states,electrical conductivity
更新于2025-09-11 14:15:04
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Effects of Hexagonal Boron Nitride Sheets on the Optothermal Performances of Quantum Dots-Converted White LEDs
摘要： Recently, quantum dots-converted white light-emitting diodes (QDs-WLEDs) are attracting numerous attention due to their high luminous efficiency and excellent color quality. As for color conversion material, the quantum dots (QDs) are commonly embedded into a low-thermal-conductivity polymer matrix. In this case, their generated heat during the photoluminescence process can hardly be dissipated into the heat sink, leading to a high working temperature and reduced lifetime. Adding particles with high thermal conductivity to the QDs layer can enhance its thermal conductivity, and thus reduce QDs’ working temperature. At the same time, these particles may affect the optical properties of QDs. However, this problem has still not been deeply studied. In this article, we systematically investigated the effects of the highly thermal-conductive hexagonal boron nitride sheets (hBNSs) on the optothermal performances of QDs/phosphor film in white light-emitting diodes (WLEDs). The thermal conductivity of QDs/phosphor film was significantly increased by 24% after adding 5wt% of 45-μm-diameter hBNS. As for the optical performance, the transparency of the silicone gel film with 45-μm-diameter hBNS was much better than that with 6–9-μm-diameter hBNS under the same weight fraction. Furthermore, the scattering effect of hBNS plays a more important role in enhancing the light conversion performance of QDs than that of phosphor. At last, a color stability test showed the increasing rate of correlated color temperature (IRCCT) of hBNS-added WLEDs are 21% smaller than that of common WLEDs after working 153 h, meaning a better QDs stability in hBNS-added WLEDs.
关键词： light conversion,quantum dots (QDs),Hexagonal boron nitride sheets (hBNSs),thermal conductivity
更新于2025-09-11 14:15:04
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Ca <sub/>3</sub> La <sub/>2</sub> Te <sub/>2</sub> O <sub/>12</sub> :Mn <sup>4+</sup> ,Nd <sup>3+</sup> ,Yb <sup>3+</sup> : an efficient thermally-stable UV/visible–far red/NIR broadband spectral converter for c-Si solar cells and plant-growth LEDs
摘要： Highly conductive PEDOT:PSS threaded HKUST-1 thin films with high porosity were prepared. The highest conductivity of these films was 13 S cm?1, nine orders of magnitude greater than that of pristine HKUST-1. A PEDOT:PSS threaded HKUST-1 thin film with 20 wt% PEDOT:PSS exhibits 300 times enhancement of the electrochemical performance of pristine HKUST-1 when applied as an electrode for thin-film-like supercapacitors.
关键词： thin films,HKUST-1,conductivity,supercapacitors,PEDOT:PSS
更新于2025-09-11 14:15:04
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Effects of end-on oriented polymer chains at the donor/acceptor interface in organic solar cells
摘要： The transport and magnetic properties of LaAlO3/SrTiO3 (LAO/STO) heterostructure have been studied during cooling and warming. The strain gradient perpendicular to the surface of the heterostructure increases with the thickness of LAO film. The conductivity accelerated recoveries (CAR) are found at 80 K and 176 K in the interface of LAO/STO sample with millimeter scale, and are more obvious for thicker LAO layers during warming. These two recovering temperatures correspond to the migrating energies of oxygen single vacancy and divacancy trapped by polarized domain walls, separately. This indicated that domain walls diffuse along the longitudinal direction and expand to larger area due the strain gradient perpendicular to the interface. The stable and precise accelerating recovering temperatures make the sample at a larger scale a potential widely applied temperature standard reference. The magnetization measurements reveal the coexistence of paramagnetic and diamagnetic in the LAO/STO samples at whole temperature from 2 K to 300 K. The abnormal electric resistance rise is observed with the decreasing temperature below 25 K for the samples of 7 and 15 LAO layers. This anomaly is attributed to the Kondo effect below 25 K and weak anti-localization below 5 K due to the weightier paramagnetic content. The larger diamagnetic content suppresses these contributions in 25 LAO layers sample. This work provided an insightful view that the strain modified structure domain leads to the enhancement of CAR effect, which helps to achieve a better understanding of domain related physics in the LAO/STO system.
关键词： magnetization,LaAlO3/SrTiO3 heterostructure,conductivity accelerated recoveries,domain walls,weak anti-localization,strain gradient,Kondo effect
更新于2025-09-11 14:15:04
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A Review on Improving the Quality of Perovskite Films in Perovskite Solar Cells via the Weak Forces Induced by Additives
摘要： It is a challenge to design intelligent thermal metamaterials due to the lack of suitable theories. Here we propose a kind of intelligent thermal metamaterials by investigating a core-shell structure, where both the core and shell have an anisotropic thermal conductivity. We solve Laplace’s equation for deriving the equivalent thermal conductivity of the core-shell structure. Amazingly, the solution gives two coupling relations of conductivity tensors between the core and the shell, which cause the whole core-shell structure to counterintuitively self-?x a constant isotropic conductivity even when the area or volume fraction of the core changes within the full range in two or three dimensions. The theoretical ?ndings on fraction-independent properties are in sharp contrast with those predicted by the well-known e?ective medium theories, and they are further con?rmed by our laboratory experiments and computer simulations. This work o?ers two coupling relations for designing intelligent thermal metamaterials, and they are not only helpful for thermal stabilization or camou?age/illusion, but they also o?er hints on how to achieve similar metamaterials in other ?elds.
关键词： Laplace’s equation,intelligent thermal metamaterials,core-shell structure,anisotropic thermal conductivity,self-fixing behavior
更新于2025-09-11 14:15:04
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Effect of an Al-doped ZnO electron transport layer on the efficiency of inverted bulk heterojunction solar cells
摘要： Doping is a widely-implemented strategy for enhancing the inherent electrical properties of metal oxide charge transport layers in photovoltaic devices because higher conductivity of electron transport layer (ETL) can increment the photocurrent by reducing the series resistance. To improve the conductivity of ETL, in this study we doped the ZnO layer with aluminum (Al), then investigated the influence of AZO on the performance of inverted bulk heterojunction (BHJ) polymer solar cells based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl]-[3-fluoro-2[(2-ethylhexyl)-carbonyl]-thieno-[3,4-b]thiophenediyl ]] (PTB7):[6,6]-phenyl C71 butyric acid methyl-ester (PC71BM). The measured conductivity of AZO was ~10-3 S/cm, which was two orders of magnitude higher than that of intrinsic ZnO (~10-5 S/cm). By decreasing the series resistance (Rs) in a device with an AZO layer, the short circuit current (Jsc) increased significantly from 15.663 mA/cm2 to 17.040 mA/cm2. As a result, the device with AZO exhibited an enhanced power conversion efficiency (PCE) of 8.984%.
关键词： ZnO,organic photovoltaics,conductivity,doping,electron transport layer
更新于2025-09-11 14:15:04
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27%‐Efficiency Four‐Terminal Perovskite/Silicon Tandem Solar Cells by Sandwiched Gold Nanomesh
摘要： Multijunction/tandem solar cells have naturally attracted great attention because they are not subject to the Shockley–Queisser limit. Perovskite solar cells are ideal candidates for the top cell in multijunction/tandem devices due to the high power conversion efficiency (PCE) and relatively low voltage loss. Herein, sandwiched gold nanomesh between MoO3 layers is designed as a transparent electrode. The large surface tension of MoO3 effectively improves wettability for gold, resulting in Frank–van der Merwe growth to produce an ultrathin gold nanomesh layer, which guarantees not only excellent conductivity but also great optical transparency, which is particularly important for a multijunction/tandem solar cell. The top MoO3 layer reduces the reflection at the gold layer to further increase light transmission. As a result, the semitransparent perovskite cell shows an 18.3% efficiency, the highest reported for this type of device. When the semitransparent perovskite device is mechanically stacked with a heterojunction silicon solar cell of 23.3% PCE, it yields a combined efficiency of 27.0%, higher than those of both the sub-cells. This breakthrough in elevating the efficiency of semitransparent and multijunction/tandem devices can help to break the Shockley–Queisser limit.
关键词： perovskite solar cells,multijunction/tandem,conductivity,transparency,nanomesh electrodes
更新于2025-09-11 14:15:04