Solar-Terrestrial Physics最新文献

{"title":"Comparison between probability density functions of vertical electric current in solar active regions based on HMI/SDO and SOT/Hinode data","authors":"A. Nechaeva, I. Zimovets, I. Sharykin","doi":"10.12737/stp-83202210","DOIUrl":"https://doi.org/10.12737/stp-83202210","url":null,"abstract":"Studying electric currents in solar active regions (AR) is an essential step in understanding solar activity in general and solar flares in particular. In this paper, we compare probability density functions of vertical electric current PDF(|jz|) in several active regions, using HMI/SDO and SOT/Hinode photospheric magnetic field data. We have established that at a high value (above the noise level of |jz| ~9•10³ statampere/cm²) of current structures of ARs these functions are nearly identical. The main difference in PDFs for low (noise) jz is due to differences in sensitivity of these two instruments. We have also found that the criterion of pixel selection from magnetic field strength is inapplicable, and the similarity between PDFs is determined by high jz. For all ARs under study we have calculated the power law exponent of the PDF tail for the two instruments, which coincide within their errors for the current structures with current values above noise level. Thus there is no significant difference as to which instrument is used for analyzing probability density functions in high current parts of ARs where flares are localized.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45313978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Connection of total electron content disturbances with AE index of geomagnetic activity during geomagnetic storm in March 2015","authors":"Kupriyan V. Belyuchenko, M. Klimenko, V. Klimenko, K. Ratovsky","doi":"10.12737/stp-83202206","DOIUrl":"https://doi.org/10.12737/stp-83202206","url":null,"abstract":"Ionospheric response to the March 17, 2015 geomagnetic storm has been investigated using simulations of the Global Self-consistent Model of the Thermosphere, Ionosphere, Protonosphere (GSM TIP) [Dmitriev et al., 2017; Klimenko et al., 2018]. GSM TIP demonstrates results that do not contradict experimental data. This paper deals with GSM TIP simulated disturbances in the Total Electron Content (TEC) at different longitudes and zonal averages on March 17–23, 2015. At all longitudes, we can observe the existence of a band of TEC positive disturbances, located over the geomagnetic equator, and the formation of an after-storm ionospheric effect that appeared as positive TEC disturbances at midlatitude 3–5 days after the geomagnetic storm main phase. We have analyzed the dependence of disturbances of the thermosphere-ionosphere system (total electron content, n(N2), n(O), zonal electric field, meridional component of the thermospheric wind at a height of 300 km, and electron temperature at a height of 1000 km), calculated by GSM TIP from variations in the geomagnetic activity index AE. The analysis is based on Pearson’s correlation coefficients, presented as maps of the dependence of the correlation coefficient on UT and latitude for selected longitudes and for zonal averaged values. The results suggest that at high latitudes of the Northern and Southern hemispheres the correlation coefficient of TEC disturbances and AE variations is close to 1 at all longitudes in the period from 12 UT to 23 UT. From 9 UT to 12 UT, the minimum value of the correlation coefficient is observed at all latitudes and longitudes. The time intervals of the correlation values are associated with the features of a particular geomagnetic storm, for which, for example, the interval from 12 UT to 23 UT on March 17, 2015 corresponds to the geomagnetic storm main phase. We discuss possible mechanisms for the formation of such a relationship between simulated TEC disturbances and the AE index.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43418604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of the spatial structure of Alfvén waves in a finite pressure plasma in a dipole magnetosphere","authors":"Aleksandr Petrashchuk, P. Mager, D. Klimushkin","doi":"10.12737/stp-83202201","DOIUrl":"https://doi.org/10.12737/stp-83202201","url":null,"abstract":"We have carried out a numerical analysis of the spatial structure of Alfvén waves in a finite pressure inhomogeneous plasma in a dipole model of the magnetosphere. We have considered three magnetosphere models differing in maximum plasma pressure and pressure gradient. The problem of wave eigenfrequencies was addressed. We have established that the poloidal frequency can be either greater or less than the toroidal frequency, depending on plasma pressure and its gradient. The problem of radial wave vector component eigenvalues was considered. We have found points of Alfvén wave reflection in various magnetosphere models. The wave propagation region in the cold plasma model is shown to be significantly narrower than that in models with finite plasma pressure. We have investigated the structure of the main Alfvén wave harmonic when its polarization changes in three magnetosphere models. A numerical study into the effect of plasma pressure on the structure of behavior of all Alfvén wave electric and magnetic field components has been carried out. We have established that for certain parameters of the magnetosphere model the magnetic field can have three nodes, whereas in the cold plasma model there is only one. Moreover, the longitudinal magnetic field component changes sign twice along the magnetic field line.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43272921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Thermal Stability of a Solar Absorber Processed through a Hydrothermal Technique","authors":"S. Abdullahi, R. Akoba, J. Sackey, S. Khamlich, S. Halindintwali, Z. Nuru, M. Maaza","doi":"10.3390/solar2040025","DOIUrl":"https://doi.org/10.3390/solar2040025","url":null,"abstract":"In this work, we study the thermal stability of a hydrothermally treated stainless steel (SS) selective solar absorber by annealing in air in a temperature range between 300 °C and 700 °C for a soaking time of 2 h. Thermal stability testing in the presence of air is critical if the vacuum is breached. Therefore, the SS was characterized by X-ray diffraction (XRD), mechanical, and optical techniques. The XRD analysis shows that the grain size of the as-treated absorber is 67 nm, whereas those of the annealed absorbers were found to be in the range between 66 and 38 nm. The phase of the as-treated and annealed SS was further identified by XRD as Fe2O3. The EDS result shows that the elemental components of the SS were C, Cr, Fe, and O. The strain (ε) and stress (σ) calculated for the as-treated absorber are 1.2 × 10−1 and −2.9 GPa, whereas the annealed absorbers are found in the range of 4.4 × 10−1 to 5.2 × 10−1 and −121.6 to −103.2 GPa, respectively, at 300–700 °C. The as-treated SS absorbers exhibit a good spectra selectivity of 0.938/0.431 = 2.176, which compares with 0.941/0.403 = 2.335 after being annealed at 300 °C and 0.884/0.179 = 4.939 after being annealed at 700 °C. These results indicate a small improvement in absorptivity (0.941) and emissivity (0.403) after annealing at 300 °C, followed by a significant decrease after annealing at 700 °C. The obtained analysis confirms that the annealed SS absorber exhibits excellent selectivity and is suitable to withstand any thermal condition (≤700 °C) in air. Thus, using a cost-effective approach as demonstrated in this study, the as-treated and annealed SS absorber could be used for photo-thermal conversion applications.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76870932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring Concentrated Solar Radiation Flux in a Linear Fresnel-Type Solar Collector","authors":"J. Fernández-Reche, L. Valenzuela, Diego Pulido-Iparraguirre","doi":"10.3390/solar2040024","DOIUrl":"https://doi.org/10.3390/solar2040024","url":null,"abstract":"Linear Fresnel solar collectors are a promising and emerging solution to contribute to renewable heat supply in industrial processes with thermal energy demand in the medium temperature range (<250 °C). An innovative linear Fresnel collector (LFC) prototype has been designed, patented, and built at the Plataforma Solar de Almería (PSA), Spain. This work presents the applied methodology, experimental device, and results obtained in the measurement of the flux density of concentrated solar radiation in the focal plane of the solar collector. The experimental results confirm that an average flux density of (9.8 ± 0.6) kW/m2 was obtained with a direct normal solar irradiance of (870 ± 10) W/m2 in tests performed in May 2002, which is a result similar to that obtained in optical simulations of the system.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89845501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Property and Stability Study of CH3(CH2)3NH3)2(CH3NH3)3Pb4I13 Ruddlesden Popper 2D Perovskites for Photoabsorbers and Solar Cells and Comparison with 3D MAPbI3","authors":"K. Kranthiraja, Sujan Aryal, Mahdi Temsal, Mohin Sharma, A. Kaul","doi":"10.3390/solar2040023","DOIUrl":"https://doi.org/10.3390/solar2040023","url":null,"abstract":"Three dimensional (3D) perovskite solar cells (PSCs) are a promising candidate for third-generation photovoltaics (PV) technology, which aims to produce efficient photon conversion devices to electricity using low-cost fabrication processes. Hybrid organic-inorganic perovskites for-lmed using low-cost solution processing are explored here, which have experienced a stupendous rise in power conversion efficiency (PCE) over the past decade and serve as a prime candidate for third-generation PV systems. While significant progress has been made, the inherent hygroscopic nature and stability issue of the 3D perovskites (3DPs) are an impediment to its commercialization. In this work, we have studied two-dimensional (2D) organometallic halide (CH3(CH2)3NH3)2(CH3NH3)n−1PbnI3n+1) layered perovskites in the Ruddlesden Popper structure, represented as BA2MA3Pb4I13 for the n = 4 formulation, for both photoabsorbers in a two-terminal architecture and solar cells, given that these material are considered to be inherently more stable. In the two-terminal photo absorber devices, the photocurrent and responsivity were measured as a function of incoming laser wavelength, where the location of the peak current was correlated to the emission spectrum arising from the 2DP film using photoluminescence (PL) spectroscopy. The 2D (BA)2(MA)3Pb4I13 films were then integrated into an n-i-p solar cell architecture, and PV device figures of merit tabulated, while our 3D MAPbI3 served as the reference absorber material. A comparative study of the 3DP and 2DP film stability was also conducted, where freshly synthesized films were inspected on FTO substrates and compared to those exposed to elevated humidity levels, and material stability was gauged using various material characterization probes, such as PL and UV-Vis optical absorption spectroscopy, scanning electron microscopy and X-ray diffraction. While the PCE of the 3D-PSCs was higher than the 2D-PSCs, our results confirm the enhanced environmental stability of the 2DP absorber films compared to the 3DP absorbers, suggesting their promise to address the stability issue broadly encountered in 3D PSCs toward third-generation PV technology.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78251434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ternary Planar Heterojunction Organic Solar Cells Based on the Ternary Active Layers: α-6T/AlPcCl/C60","authors":"H. Ftouhi, H. Lamkaouane, M. Diani, G. Louarn, L. Arzel, J. Bernède, M. Addou, L. Cattin","doi":"10.3390/solar2030022","DOIUrl":"https://doi.org/10.3390/solar2030022","url":null,"abstract":"Ternary planar heterojunction organic solar cells (PHJ-OPVs) were fabricated using three organic small molecules, alpha-sexithiophene (α-6T), aluminum phthalocyanine chloride (AlPcCl) and fullerene (C60). These molecules can be easily sublimated under a vacuum; they have complementary optical absorption spectra and their energy band structure alignment is favorable for electronic charge transfers. Moreover, α-6T and AlPcCl have almost the same HOMO, which is desirable to avoid any decrease in open circuit voltage. The AlPcCl intercalated layer bridges the energy levels of the electron donor, α-6T, and the electron acceptor, C60, which facilitates charge transport through the energy cascade effect. Moreover, the charge carrier mobility measurements of AlPcCl, using the space charge limited current method, demonstrated that it iss ambipolar. All these properties combine to improve the power conversion efficiency (PCE) of PHJ-OPVs by moving from binary structures (α-6T/C60, α-6T/AlPcCl and AlPcCl/C60) to ternary ones (α-6T/AlPcCl/C60). We show, in this study, that both interfaces of the ternary PHJ-OPVs are efficient for carrier separation. After optimization of the different layer thickness, we show that, by comparing the optimum efficiencies of the binary PHJ-OPVs, the realization of ternary PHJ-OPVs, based on the active layers α-6T/AlPcCl/C60, using the following optimized method, allows us to achieve a PCE of 4.33%.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87015089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Satellite-Based and Ångström–Prescott Estimated Global Horizontal Irradiance under Different Cloud Cover Conditions in South African Locations","authors":"Brighton Mabasa, M. Lysko, S. J. Moloi","doi":"10.3390/solar2030021","DOIUrl":"https://doi.org/10.3390/solar2030021","url":null,"abstract":"The study compares the performance of satellite-based datasets and the Ångström–Prescott (AP) model in estimating the daily global horizontal irradiance (GHI) for stations in South Africa. The daily GHI from four satellites (namely SOLCAST, CAMS, NASA SSE, and CMSAF SARAH) and the Ångström–Prescott (AP) model are evaluated by validating them against ground observation data from eight radiometric stations located in all six macro-climatological regions of South Africa, for the period 2014-19. The evaluation is carried out under clear-sky, all-sky, and overcast-sky conditions. CLAAS-2 cloud fractional coverage data are used to determine clear and overcast sky days. The observed GHI data are first quality controlled using the Baseline Surface Radiation Network methodology and then quality control of the HelioClim model. The traditional statistical benchmarks, namely the relative mean bias error (rMBE), relative root mean square error (rRMSE), relative mean absolute error (rMAE), and the coefficient of determination (R2) provided information about the performance of the datasets. Under clear skies, the estimated datasets showed excellent performance with maximum rMBE, rMAE, and rRMSE less than 6.5% and a minimum R2 of 0.97. In contrast, under overcast-sky conditions there was noticeably poor performance with maximum rMBE (24%), rMAE (29%), rRMSE (39%), and minimum R2 (0.74). For all-sky conditions, good correlation was found for SOLCAST (0.948), CMSAF (0.948), CAMS (0.944), and AP model (0.91); all with R2 over 0.91. The maximum rRMSE for SOLCAST (10%), CAMS (12%), CMSAF (12%), and AP model (11%) was less than 13%. The maximum rMAE for SOLCAST (7%), CAMS (8%), CMSAF (8%), and AP model (9%) was less than 10%, showing good performance. While the R2 correlations for the NASA SSE satellite-based GHI were less than 0.9 (0.896), the maximum rRMSE was 18% and the maximum rMAE was 15%, showing rather poor performance. The performance of the SOLCAST, CAMS, CMSAF, and AP models was almost the same in the study area. CAMS, CMSAF, and AP models are viable, freely available datasets for estimating the daily GHI at South African locations with quantitative certainty. The relatively poor performance of the NASA SSE datasets in the study area could be attributed to their low spatial resolution of 0.5° × 0.5° (~55 km × 55 km). The feasibility of the datasets decreased significantly as the proportion of sky that was covered by clouds increased. The results of the study could provide a basis/data for further research to correct biases between in situ observations and the estimated GHI datasets using machine learning algorithms.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74031024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparative Study of Quantum Dot Solar Cell with Two Different ETLs of WS2 and IGZO Using SCAPS-1D Simulator","authors":"Naureen, Sadanand, P. Lohia, D. K. Dwivedi, S. Ameen","doi":"10.3390/solar2030020","DOIUrl":"https://doi.org/10.3390/solar2030020","url":null,"abstract":"Quantum dot solar cells have received significant attention in comparison to standard solar cells because of their hybrid nature, low production costs, and higher power conversion efficiency. Although quantum dot solar cells (QDSCs) have several benefits over ordinary solar cells, their performance lags due to carrier combination within the quasi-neutral region (QNR). The electron transport layer (ETL) and hole transport layer (HTL) are the two layers that have the most effect on QDSC performance. This numerical analysis is carried out by using the Solar Cell Capacitance Simulator-1 dimensional software (SCAPS-1D). In this paper, the optimization of two different device structure investigations is performed. In this proposed device structure, WS2 and IGZO are used as two ETL, CdS is used as a buffer layer, Sb2Se3 is used as an absorber layer, and PbS as HTL. Initially, the optimization of the device has been performed, followed by depth analysis of the doping densities. Resistance analysis is also performed to illustrate the effect of resistance on the device. Further, the impact of temperature on the device parameters is also represented, followed by a contour plot between thickness and bandgap for both devices. The impact of the series and shunt resistance on the performance of the solar cell is investigated. The effect of temperature is studied further, and it is observed that the solar device is temperature-sensitive. Finally, the optimized performance with IGZO ETL with PCE of 20.94% is achieved.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75001008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Bandgap Mixed Tin–Lead Perovskite Solar Cells","authors":"Jingwei Zhu, Cong Chen, Dewei Zhao","doi":"10.3390/solar2030019","DOIUrl":"https://doi.org/10.3390/solar2030019","url":null,"abstract":"Low-bandgap mixed tin (Sn)–lead (Pb) perovskite solar cells have been extensively investigated in the past few years due to their great potential in high-performance perovskite/perovskite tandem solar cells. From this perspective, we briefly summarize the mechanism of understanding of additives and the advances in the efficiency and stability of such low-bandgap Sn-Pb perovskite materials and solar cells in terms of various effective strategies for suppressing the defects and oxidation of Sn2+, regulating crystallization growth, etc. We then provide a perspective regarding the achievement of high-quality, low-bandgap Sn-Pb perovskites and highly efficient solar cells.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77744657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}