Search results for "Cèl·lules fotoelèctriques"
showing 10 items of 54 documents
The shiny side of copper: bringing copper(i) light-emitting electrochemical cells closer to application
2020
Heteroleptic [Cu(P^P)(N^N)][PF6] complexes, where N^N is 5,50-dimethyl-2,20-bipyridine (5,50-Me2bpy), 4,5,6-trimethyl-2,20-bipyridine (4,5,6-Me3bpy), 6-(tert-butyl)-2,20-bipyridine (6-tBubpy) and 2-ethyl-1,10- phenanthroline (2-Etphen) and P^P is either bis(2-(diphenylphosphino)phenyl)ether (POP, PIN [oxydi(2,1- phenylene)]bis(diphenylphosphane)) or 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos, PIN (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane)) have been synthesized and their NMR spectroscopic, mass spectrometric, structural, electrochemical and photophysical properties were investigated. The single-crystal structures of [Cu(POP)(5,50-Me2bpy)][PF6], [Cu(xantphos)(5,…
Applications of vacuum vapor deposition for perovskite solar cells: A progress review
2022
Metal halide perovskite solar cells (PSCs) have made substantial progress in power conversion efficiency (PCE) and stability in the past decade thanks to the advancements in perovskite deposition methodology, charge transport layer (CTL) optimization, and encapsulation technology. Solution-based methods have been intensively investigated and a 25.7% certified efficiency has been achieved. Vacuum vapor deposition protocols were less studied, but have nevertheless received increasing attention from industry and academia due to the great potential for large-area module fabrication, facile integration with tandem solar cell architectures, and compatibility with industrial manufacturing approach…
Simple approach for an electron extraction layer in all-vacuum processed n-i-p perovskite solar cell
2021
Vacuum processing is considered to be a promising method allowing the scalable fabrication of perovskite solar cells (PSCs). In vacuum processed PSCs, the n-i-p structure employing organic charge transport layers is less common than the p-i-n structure due to limited options to achieve an efficient electron extraction layer (EEL) on indium tin oxide (ITO) with vacuum thermal evaporation. There are a number of specific applications where an n-i-p structure is required and therefore, it is of interest to have alternative solutions for the n-type contact in vacuum processed PSCs. In this work, we report an efficient vacuum deposited EEL using a mixture of conventional organic small molecules, …
Perovskite Solar Cells: Stable under Space Conditions
2020
Metal halide perovskite solar cells (PSCs) are of interest for high altitude and space applications due to their lightweight and versatile form factor. However, their resilience toward the particle spectrum encountered in space is still of concern. For space cells, the effect of these particles is condensed into an equivalent 1 MeV electron fluence. The effect of high doses of 1 MeV e-beam radiation up to an accumulated fluence to 10^16 e-cm-2 on methylammonium lead iodide perovskite thin films and solar cells is probed. By using substrate and encapsulation materials that are stable under the high energy e-beam radiation, its net effect on the perovskite film and solar cells can be studied.…
Efficient Vacuum Deposited P-I-N Perovskite Solar Cells by Front Contact Optimization.
2020
Hole transport layers HTLs are of fundamental importance in perovskite solar cells PSCs , as they must ensure an efficient and selective hole extraction, and ohmic charge transfer to the corresponding electrodes. In p i n solar cells, the ITO HTL is usually not ohmic, and an additional interlayer such as MoO3 is usually placed in between the two materials by vacuum sublimation. In this work, we evaluated the properties of the MoO3 TaTm TaTm is the HTL N4,N4,N4 amp; 8243;,N4 amp; 8243; tetra [1,1 amp; 8242; biphenyl] 4 yl [1,1 amp; 8242; 4 amp; 8242;,1 amp; 8243; terphenyl] 4,4 amp; 8243; diamine hole extraction interface by selectively annealing either MoO3 prior to the deposition of TaTm o…
Hybrid Vapor-Solution Sequentially Deposited Mixed-Halide Perovskite Solar Cells
2020
The recent sky-rocketing performance of perovskite solar cells has triggered a strong interest in further upgrading the fabrication techniques to meet the scalability requirements of the photovoltaic industry. The integration of vapor-deposition into the solution process in a sequential fashion can boost the uniformity and reproducibility of the perovskite solar cells. Besides, mixed-halide perovskites have exhibited outstanding crystallinity as well as higher stability compared with iodide-only perovskite. An extensive study was carried out to identify a reproducible process leading to highly crystalline perovskite films that when integrated into solar cells exhibited high power conversion…
Quadruple-Cation Wide-Bandgap Perovskite Solar Cells with Enhanced Thermal Stability Enabled by Vacuum Deposition.
2022
Vacuum processing of multicomponent perovskites is not straightforward, because the number of precursors is in principle limited by the number of available thermal sources. Herein, we present a process which allows increasing the complexity of the formulation of vacuum-deposited lead halide perovskite films by multisource deposition and premixing both inorganic and organic components. We apply it to the preparation of wide-bandgap CsMAFA triple-cation perovskite solar cells, which are found to be efficient but not thermally stable. With the aim of stabilizing the perovskite phase, we add guanidinium (GA+) to the material formulation and obtained CsMAFAGA quadruple-cation perovskite films wi…
Perovskite/Perovskite Tandem Solar Cells in the Substrate Configuration with Potential for Bifacial Operation.
2022
Perovskite/perovskite tandem solar cells have recently exceeded the record power conversion efficiency (PCE) of single-junction perovskite solar cells. They are typically built in the superstrate configuration, in which the device is illuminated from the substrate side. This limits the fabrication of the solar cell to transparent substrates, typically glass coated with a transparent conductive oxide (TCO), and adds constraints because the first subcell that is deposited on the substrate must contain the wide-bandgap perovskite. However, devices in the substrate configuration could potentially be fabricated on a large variety of opaque and inexpensive substrates, such as plastic and metal fo…
Effects of Masking on Open-Circuit Voltage and Fill Factor in Solar Cells
2019
Guidelines for the correct measurement protocol of novel photovoltaic technologies such as perovskites are becoming more frequent in literature. This because, as will be confirmed in this perspective, it is not straightforward to correctly measure the efficiency parameters of these and many other novel solar cells. This is particularly the case for small area research devices which are prone to overestimate the short circuit current density, due to edge effects of various types. To reduce the inaccuracy of current density determination, the common recommended practice is to utilize masks with well‐defined apertures, often smaller than the device active area. Herein we show both experimental…
Room-Temperature Cubic Phase Crystallization and High Stability of Vacuum-Deposited Methylammonium Lead Triiodide Thin Films for High-Efficiency Sola…
2019
Methylammonium lead triiodide (MAPI) has emerged as a high-performance photovoltaic material. Common understanding is that at room temperature it adopts a tetragonal phase and it only converts to the perfect cubic phase around 50-60 ºC. Most MAPI films are prepared using a solution-based coating process, yet they can also be obtained by vapor phase deposition methods. Vapor phase processed MAPI films have significantly different characteristics compared to their solvent processed analogous, such as a relatively small crystal grain sizes and short excited state lifetimes. Yet solar cells based on vapor phase processed MAPI films exhibit high power conversion efficiencies. Surprisingly, after…