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Large‐scale manufacturing of perovskite solar cells (PSCs) requires the deposition of homogeneous and defect‐free perovskite films on large‐area substrates. Up to now, the knowledge developed for industrial slot‐die processing has not been fully transferred to the perovskite photovoltaic community. Here, the deposition of uniform perovskite layers by slot‐die coating (SDC). Computer fluid dynamics (CFD) simulations, experimental validation, and calculation of industrial uniformity parameters are demonstrated, which enabled to establish processing conditions for SDC of perovskite ink. This approach allowed for obtaining stable cross‐web flow in the slot‐die head resulting in the formation of a stable coating bead yielding uniform perovskite films. The best processing parameters are used for the fabrication of slot‐die‐coated PSCs, which showed a more homogeneous spatial distribution of photovoltaic parameters compared to their spin‐coated counterparts. Better reproducibility observed in device performance is a step forward toward the commercialization of perovskite photovoltaic technology. For the first time, the industrial approach used for the optimization of slot‐die coating is applied for the processing of perovskite inks that have special conditions such as low viscosity and in situ crystallization on the substrate. [ABSTRACT FROM AUTHOR]

Perovskite solar technology stands on three different pillars: efficiency, stability, and processability. Focusing on processability, the field demands the achievement of optoelectronic grade active layers with high uniformity fabricated by industry‐compatible methods. Herein, the design and implementation of an air knife on a blade coating deposition system, which allows controlling the evaporation rate of the solvents improving the crystallization and uniformity of perovskite films in a p–i–n device are reported. The effect of doctor blade operational parameters is studied using image analysis combined with a machine learning method to identify the most relevant processing variables leading to a uniform perovskite layer with optimal thickness. After implementing the air knife system and finding the best processing conditions, a special perovskite solar minimodule enabling the evaluation of single inner subcells is fabricated. These perovskite subcells reach an average efficiency of 10.1% and remarkably all the subcells deviate less than 20% from this value over a large‐area substrate. These results demonstrate the promising potential of this fabrication method for low cost and high deposition rate photovoltaic devices, which is on the path to mass production. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized and fabricated solar cells with the hybrid metal halide compounds with the general formula ABX3, where the A cation is methylammonium, the B cation is nickel, and the X anion is chlorine or a mixture of chlorine and iodine. We obtained experimental evidence that this material is a semiconductor with an orthorhombic crystalline structure which pertains to the space group Cmcm. The bandgap can be modulated from 1.4 eV to 1.0 eV by changing the chlorine anion to iodine. Therefore, we were able to obtain solar cells with efficiencies up to 0.16% with the CH3NH3NiCl2I composition. We have also studied by means of first-principles calculations, taking into account van der Waals dispersive forces, the ground state properties of these materials such as their crystal structure and formation and decomposition energies. We have found that these energies are lowered by the lighter mass anion, and the calculated decomposition energies show that only CH3NH3NiCl3 is stable with respect to the most probable decomposition pathway. The electronic band structure and band edge alignments have been calculated using quasiparticle effects through the GW0 approximation; these materials show an indirect bandgap with the valence band maxima at −6.93 and −5.49 eV with respect to vacuum and the conduction band minima at −5.62 and −4.60 eV with respect to vacuum for CH3NH3NiCl3 and CH3NH3NiI3, respectively. This work provides a pathway to explore new hybrid A + B 2 + X 3 − -type semiconductor materials. [ABSTRACT FROM AUTHOR]

Abstract: A way to upscale the manufacture of organic solar cells is through roll-to-roll processing in which is required to develop fully solution-processed devices. However, deposition via solution of opaque electrodes as final layer on top of the device stack has shown to still be challenging. In this work we present a simple method to develop such electrode based on silver plate-shaped micro-particles. We demonstrate that this electrode do not affect the underlying device structure while providing an optimal performance in terms of low sheet resistance and electrical stability. The final fabricated devices achieved up to 2.2% efficiency and very low device series resistance values. [Copyright &y& Elsevier]

With the aim to determine the photo-generated current, diode saturation current, ideality factor, shunt, and series resistances related to the one-diode model for p-i-n planar perovskite solar cells, reference cells with active area of approximately 1 cm2 and efficiencies ranging between 4.6 and 12.2% were fabricated and characterized at standard test conditions. To estimated feasible parameters, the mean square error between the I-V curve data of these cells and the circuital model results were minimized using a Genetic Algorithm combined with the Nelder-Mead method. When considering the optimization process solutions, a numerical sensitivity analysis of the error as a function of the estimated parameters was carried out. Based on the errors behavior that is showed graphically through maps, it was demonstrated that the set of parameters estimated for each cell were reliable, meaningful, and realistic, and being related to errors lower than 9.1 × 10−9. Therefore, these results can be considered as global solutions of the optimization process. Moreover, based on the lower errors obtained from the optimization process, it was possible to affirm that the one-diode model is suitable to model the I-V curve of perovskite solar cells. Finally, the estimated parameters suggested that the average ideality factor is close to 2 when the fill factor of the I-V curves is higher than 0.5. Lower fill factors corresponded to ideality that was higher than 3, linked to lower efficiencies, and high loses effects reflected on lower shunt resistances. Lower ideality factor of 1.4 corresponds to the best performing solar cells. [ABSTRACT FROM AUTHOR]

• Impact of irradiance and temperature on the PV outdoor performance. • NOCT as a suitable condition to evaluate performance of PV. • Continuous outdoor monitoring of solar devices. In order to evaluate the impact of irradiance and temperature on the outdoor performance of solar devices, a monitoring system including electronic analyzers for measuring the I-V curve and a data management to store, synchronize and process the electrical and weather records were developed. With this system, the average performance as a function of irradiance and temperature of commercial solar panels was obtained in natural sunlight without tracker considering up to 4700 h of exposure and sampling time of 1 min. Besides, the data were processed considering the irradiance levels defined by each power rating conditions suggested by IEC 61853. The results indicated that in tropical weather the Standard Test Conditions (STC) are not as representative to evaluate solar panels, due that an irradiance of 1000 W/m2 rarely occurs at 25 °C temperature of the panel. However, the Nominal Operative Cell Temperature (NOCT) was the most suitable condition to test outdoor performance according to the manufacturer data. Therefore, this condition could be considered to evaluate the status of devices and to define the maintenance guidelines of photovoltaic devices. Finally, the NOCT behavior over time suggested that between 200 and 600 h of exposure are more than enough to characterize and obtain reliable Power Rating Conditions (PRC) under the local conditions. [ABSTRACT FROM AUTHOR]

Hybrid organic/inorganic perovskite materials have become promising candidates for photovoltaic applications. Typically, lab-scale perovskite devices are fabricated by spin coating under inert atmosphere conditions (inert gases and low relative humidity) which is incompatible with scaling-up processing. In this paper, we report the fabrication of perovskite solar cells in ambient conditions (average 65% relative humidity) and low temperature, by using a slot-die technique in a Mini Roll coater. A detailed optimization of the deposition parameters for the constituent layers in a flexible and planar perovskite solar cell is discussed. In particular, the resulting layers morphology strongly depended upon the processing temperature. The optimized device architecture reached a power conversion efficiency up to 2.9% with good reproducibility and reporting forward and reverse performance. The obtained results suggest that the slot-die processing of flexible hybrid perovskite solar cells at ambient conditions can be achieved with significantly reduced production costs and reliable and scalable technology. [ABSTRACT FROM AUTHOR]

• Novel hybrid CH 3 NH 3 NiCl 3 material is proposed for lithium ion battery application. • CH 3 NH 3 NiCl 3 showed high capacity of 650 mAh g−1 and high reversibility. • CH 3 NH 3 NiCl 3 is obtained from lead and cobalt-free precursors. • CH 3 NH 3 NiCl 3 has 2D pathways with enough space for Li intercalation. Organic−inorganic hybrid materials have recently been investigated in a variety of applications, including solar cells and batteries. Due to its simple processing, abundant precursors, and high availability of structural space to host lithium atoms, in this work the nickel-based hybrid material CH 3 NH 3 NiCl 3 (MANiCl 3) was assessed for first time for lithium ion battery application. The battery electrodes made with this active material showed a remarkable initial capacity of 650 mAh g−1, with a coulombic efficiency of ca. 100% during cycling, and charge retention of ca. 55% after the 19th cycle at current density of ca 32 mA g−1. A reaction mechanism for the charge/discharge processes of the MANiCl 3 active material was also proposed, and we found that three reaction steps occur for this material. The first of these corresponds to the lithium intercalation (Li+ insertion/extraction) inside the MANiCl 3 structure; the second is a conversion of the active material into chloride salts; and finally an alloying process occurs between lithium and nickel atoms, leading to intermetallic Li x Ni y compounds. We suggest that the conversion and alloying processes may be irreversible and are responsible for the capacity decay during cycling. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract The relevance of perovskite photovoltaics is fully supported by its impressive development in recent years. Besides high efficiency, adoption of this technology requires obtaining long operational stability and cost-effective fabrication methods of large area devices. With the current perovskite solar cell (PSC) configurations (planar or meso n-i-p), it is difficult to deposit uniform pin-hole free films over large area at low temperature (<100 °C). In order to solve the above issues, we adopt a fabrication strategy for the scaling up of perovskite solar cells. Particularly, we study and fabricate a meso-superstructured p-type/intrinsic/n-type (p-i-n) cell (p-i-n-meso) configuration in which the insulating mesoporous layer of Al 2 O 3 plays a key role in the fabrication of perovskite solar modules and therefore we also draw attention to this structure that has been out of the map for the fabrication of large area perovskite devices. The potential of this architecture is demonstrated through fabrication of devices ranging from small area (9 mm2) up to eight-cell CH 3 NH 3 PbI 3 perovskite modules over substrates as large as 100 cm2. A record photovoltaic conversion efficiency (PCE) of 9.3% and geometrical fill factor (GFF) of 84% was reached for a module with 17 cm2 of active area. Additionally, we carried out an in-situ monitoring of the photovoltaic parameters of one perovskite module for 2000 h under outdoor conditions, giving evidence of the high performance and stability of encapsulated perovskite photovoltaic technology in a real operational environment. This study paves the way to the upscaling of stable, efficient and full-solution-processed PSCs. Graphical abstract p-i-n-MSSC perovskite solar cell architecture with superior performance, stability and scalability. Image 1 Highlights • Development of perovskite solar modules using a p-i-n mesoporous architecture which enables improved stability and reproducibility. • Large area devices fabricated by full solution processes at low temperature. • Evaluation of perovskite technology under real operational conditions. • Monitoring of the performance of perovskite photovoltaic technology for 2000 h in outdoor conditions. [ABSTRACT FROM AUTHOR]

Abstract One of the challenges in the field of perovskite solar cells (PSC) is the development of inorganic hole-transporting-materials (HTM) suitable for solution-processed deposition, in order to have cheaper, more stable and scalable devices. Herein, we report the synthesis and characterization of p-type copper sulfide nanoparticles for their application for the first time as a low-cost, fully-inorganic HTM in mesoscopic n-i-p PSC. By employing CuS combined with two different perovskites, CH 3 NH 3 PbI 3 (MAPbI 3) and (FAPbI 3) 0.78 (MAPbBr 3) 0.14 (CsPbI 3) 0.08 (CsFAMAPbIBr), very high current densities and fill-factors are observed, suggesting an effective hole-extraction happening at the CuS interface. Noticeable, our cells exhibit one of the highest power conversion efficiencies (PCE) in n-i-p configuration employing a sole solution-processed inorganic HTM via non-toxic solvents, leading to 13.47% and 11.85% for MAPbI 3 and CsFAMAPbIBr, respectively. As a remark, such PCE values are only limited by a reduced open-circuit voltage around 0.8 V, due to different phenomena occurring at perovkite/CuS interface such as an increased non-radiative recombination, caused by considerable difference in valence band value, and the effect of CuS metallic character. Overall, these findings highlight CuS as an extremely cheap alternative to common organic HTMs and pave the way to new improvements employing this material in full-inorganic blocking layers PSC. Graphical abstract Unlabelled Image Highlights • High performance CuS layers as sole HTM in perovskite solar cells (PSC) • PSC with 13.47% efficiency employing CuS as extremely low-cost HTM • PSC performance dominated by charge recombination in Perovskite/CuS interface • CuS metallic character influences device performance. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have emerged as an alternative photovoltaic technology reaching record certified efficiencies of 20.1% in only 6 years. Film morphology and crystalline structure of the perovskite are crucial factors to determine the final photovoltaic performance. In this work, the thermal transitions occurring during the crystallization of the CH 3 NH 3 PbI 3− x Cl x perovskite were revealed by differential scanning calorimetry (DSC). Particularly, the calorimetric analysis suggest that an annealing temperature around 130 °C drives to better ordered perovskite structures as confirmed by X-ray diffraction (XRD) analysis. Indeed, the photovoltaic performance of the devices developed at such optimal temperature reached 8.7% average PCE which is in the state-of-the-art for the considered pin planar PSC. Our experimental observations highlight the relevance of DSC as a powerful tool to determine in situ the CH 3 NH 3 PbI 3− x Cl x optimal crystallization conditions. This analysis provides a better understanding of the physical processes occurring during the perovskite crystallization and has the potential to be applied in the optimization of novel photovoltaic materials and structures. [ABSTRACT FROM AUTHOR]

• Mn2+ 4T 1 and Cd-Cd levels are formed into Mn-CdS after chalcogenide preparation. • Cd–Cd→Mn2+ 4T 1 carrier transitions improve the light-harvesting of the photoanodes. • The load of Mn-CdS QDs impacts on the charge transport ability of the photoanodes. • Mn2+ 4T 1 states provide a suitable band alignment in the composite heterostructure. • The Cd–Cd→Mn2+ 4T 1 interaction increases the electron lifetime into photoanodes. Low-band gap chalcogenides such as Bi 2 S 3 (<1.7 eV) have been widely used in optoelectronic devices such as quantum dot sensitized solar cells (QDSSCs), due to their high sunlight harvesting capability, absorbing low-energy photons close to the IR region. Nonetheless, Bi 2 S 3 offers a poor band alignment with large-band gap semiconductors such as TiO 2 , achieving low photoconversion efficiencies. Accordingly, we studied how the presence of both Mn2+ 4T 1 ligand field electronic states and structural defects as Cd–Cd energy levels produced during Mn-CdS synthesis influenced on the band structure and thereby, the charge carrier transport into co-sensitized boron, nitrogen and fluorine-co-doped TiO 2 nanotubes (X–Mn–Y–CdS–Bi 2 S 3). Carrier transfer pathways provided by both Cd–Cd defects and Mn2+ 4T 1 states allowed to obtain a suitable 0.7–Mn–4–CdS–2–Bi 2 S 3 based electrode, with a narrowed band gap of 2.16 eV and an appropriate II-type heterostructure. These features improved both the carrier separation and mobility from Mn-CdS/Bi 2 S 3 interface to co-doped nanotubes. Additionally, the electron lifetime into the composite photoanode was 10 times higher compared with a Mn2+-absent 4–CdS–2–Bi 2 S 3 material. Hence, the synergistic behavior between structural defects and ligand field electronic states explained here offers an insight for establishing adequate heterostructures to be useful in QDSSCs. [ABSTRACT FROM AUTHOR]