@article{65270, abstract = {{In perovskite solar cells (PSCs), electron transport layers (ETLs) play an important role in the selection and transport of electrons. Understanding the properties of these layers in relation to device performance is essential for optimizing solar cell efficiency and enabling their integration into emerging architectures, such as flexible solar cells. Here, we deposited TiO2 at different thicknesses using atomic layer deposition (ALD), a technique well-suited for producing uniform and pinhole-free films. The crystal structure of the layers was controlled by depositing the films at three different temperatures: 150 °C, 250 °C, and 350 °C. The layers were characterized in detail to determine the morphology (by atomic force microscopy), surface composition (by X-ray photoelectron spectroscopy) and the crystal structure (by X-ray diffraction). The TiO2 layers were then incorporated as ETLs in planar perovskite solar cells to evaluate their influence on device performance. Higher deposition temperatures led to improvements in device fill factor and open-circuit voltage, leading to more efficient solar cells. Notably, the best device performance for the ALD-TiO2 layers was achieved with films deposited at 250 °C.}}, author = {{Qudsia, Syeda and Weiss, Alexander and Sirkiä, Saara and Wang, Fuzeng and Rosqvist, Emil and Los Arcos, Teresa De and Weinberger, Christian and Halme, Janne and Kemell, Marianna and Smått, Jan-Henrik}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, keywords = {{Titanium dioxide, Atomic layer deposition, Electron transport layer, Perovskite solar cells}}, pages = {{166755}}, title = {{{Influence of deposition temperature and thickness of ALD-TiO2 on planar perovskite solar cell performance}}}, doi = {{https://doi.org/10.1016/j.apsusc.2026.166755}}, year = {{2026}}, } @inproceedings{24551, abstract = {{Access to precise meteorological data is crucial to be able to plan and install renewable energy systems such as solar power plants and wind farms. In case of solar energy, knowledge of local irradiance and air temperature values is very important. For this, various methods can be used such as installing local weather stations or using meteorological data from different organizations such as Meteonorm or official Deutscher Wetterdienst (DWD). An alternative is to use satellite reanalysis datasets provided by organizations like the National Aeronautics and Space Administration (NASA) and European Centre for Medium-Range Weather Forecasts (ECMWF). In this paper the “Modern-Era Retrospective analysis for Research and Applications” dataset version 2 (MERRA-2) will be presented, and its performance will be evaluated by comparing it to locally measured datasets provided by Meteonorm and DWD. The analysis shows very high correlation between MERRA-2 and local measurements (correlation coefficients of 0.99) for monthly global irradiance and air temperature values. The results prove the suitability of MERRA-2 data for applications requiring long historical data. Moreover, availability of MERRA-2 for the whole world with an acceptable resolution makes it a very valuable dataset.}}, author = {{Khatibi, Arash and Krauter, Stefan}}, booktitle = {{Proceedings of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC 2021)}}, isbn = {{3-936338-78-7}}, keywords = {{Energy potential estimation, Photovoltaic, Solar radiation, Temperature measurement, Satellite data, Meteonorm, MERRA-2, DWD}}, pages = {{1141 -- 1147}}, title = {{{Comparison and Validation of Irradiance Data: Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather Service (DWD)}}}, doi = {{10.4229/EUPVSEC20212021-5BV.4.11}}, year = {{2021}}, } @article{21265, abstract = {{Fast-growing energy demand of the world makes the researchers focus on finding new energy sources or optimizing already-developed approaches. For an efficient use of solar and wind energy in an energy system, correct design and sizing of a power system is of high importance and improving or optimizing the process of data obtaining for this purpose leads to higher performance and lower cost per unit of energy. It is essential to have the most precise possible estimation of solar and wind energy potential and other local weather parameters in order to fully feed the demand and avoid extra costs. There are various methods for obtaining local data, such as local measurements, official organizational data, satellite obtained, and reanalysis data. In this paper, the Modern-Era Retrospective analysis for Research and Applications dataset version 2 (MERRA-2) dataset provided by NASA is introduced and its performance is evaluated by comparison to various locally measured datasets offered by meteorological institutions such as Meteonorm and Deutscher Wetterdienst (DWD, or Germany’s National Meteorological Service) around the world. After comparison, correlation coefficients from 0.95 to 0.99 are observed for monthly global horizontal irradiance values. In the case of air temperature, correlation coefficients of 0.99 and for wind speed from 0.81 to 0.99 are observed. High correlation with ground measurements and relatively low errors are confirmed, especially for irradiance and temperature values, that makes MERRA-2 a valuable dataset, considering its world coverage and availability.}}, author = {{Khatibi, Arash and Krauter, Stefan}}, issn = {{1996-1073}}, journal = {{Energies}}, keywords = {{Solar irradiance, MERRA 2, Meteonorm, DWD}}, number = {{4}}, publisher = {{MDPI}}, title = {{{Validation and Performance of Satellite Meteorological Dataset MERRA-2 for Solar and Wind Applications}}}, doi = {{10.3390/en14040882}}, volume = {{14}}, year = {{2021}}, } @inproceedings{16899, abstract = {{To compare efficiency and yield of many micro-inverters available on the world market in 2014-2020, an in- and outdoor test laboratory at the University of Paderborn has been set up. The inverters have been fed by identical and calibrated crystalline silicon PV modules of 215 Wp. To monitor accurately DC input, AC power output and energy yield, each of the micro-inverters has been equipped with a calibrated electricity meter. For micro-inverters requiring control units for grid-feeding that has been acquired also. The comparison covers efficiency-load characteristics as well as electrical energy yields. Purchase costs vary considerably between the models in comparison, sometimes inverter costs are higher than module costs, particularly if an additional grid-connection or interface device is needed for operation. The weighted conversion efficiency according to EU and CEC standards has been measured and calculated. While some inverters have been optimized for high irradiance levels, they ranked better at the CEC efficiency, others performed very well also for low irradiance levels, thus ranking higher at in the EU-efficiency tables. These results are deviating from the actual energy yield measurements, which show a slightly different ranking. At one inverter, an accurate, but very slow MPPT algorithm that barely could follow quickly changing irradiance levels could be the reason for this effect. Another inverter switched off after operation at high power output for a while. Apparently, some inverters are been optimized to show excellent EU and CEC efficiency ratings. Two of the inverters featuring two inputs did not show an exceptional performance at the EU- and CEC-ratings, but they achieved top ranks at the AC energy yield for the first years. For the customer, the AC yield is a major performance indicator of any microinverter and should be included in the datasheet.}}, author = {{Krauter, Stefan and Bendfeld, Jörg}}, booktitle = {{Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING}}, issn = {{ 0160-8371}}, keywords = {{yield, AC, micro-inverter, MPPT, CEC rating, EU efficiency, Photovoltaic, Solar}}, location = {{VIRTUAL MEETING}}, pages = {{1429--1432}}, publisher = {{IEEE}}, title = {{{Comparison of Microinverters: Update on Rankings of Conversion Efficiencies and Energy Yields}}}, doi = {{10.1109/PVSC45281.2020.9300953}}, year = {{2020}}, } @article{62811, abstract = {{The photo-conversion efficiency and stability of back-illuminated dye sensitised solar cells with titanium foil based photoanodes are enhanced by a simple nitric acid treatment through which the foil is passivated. This treatment changes the morphology of the titanium foil and increases its electrochemical double layer capacitance.}}, author = {{Linnemann, Julia and Giorgio, J. and Wagner, K. and Mathieson, G. and Wallace, G. G. and Officer, D. L.}}, issn = {{2050-7488}}, journal = {{Journal of Materials Chemistry A}}, keywords = {{dye sensitized solar cells, DSSCs}}, number = {{7}}, pages = {{3266--3270}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{A simple one step process for enhancement of titanium foil dye sensitised solar cell anodes}}}, doi = {{10.1039/c4ta05407e}}, volume = {{3}}, year = {{2015}}, }