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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]

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]

We studied the performance over time of opaque and semi-transparent PTB7:PC71BM bulk hetero-junction solar cells. For unsealed inverted configuration cells we observe that when the isolation from the environment is improved, the degradation observed is dominated by one single exponential decay. We demonstrate that a dielectric multilayer stack of approximately 550 nm provides an isolation that increases the lifetime of the cell close to ten times. In that event the fill factor appears to be the PV parameter dominating cell degradation resulting from a decrease in the shunt resistance. An Impedance analysis we performed indicates that a Warburg element, attributed to the presence of slowly moving charges such as heavy ions, must be included in the description of the experimental data. The contribution from such element increases as the cell degrades in good agreement with a degradation dominated by the corrosive effects from external agents reaching the active layer of the device. [ABSTRACT FROM AUTHOR]

An optical metal cavity configurationis used to trap near infrared light in a semitransparent organic solar cell. The efficiency for such cell, which has a higher than 20% transparency in the visible region, is equal to 90% of the efficiency of the corresponding opaque cell. [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]

Organic solar cells have unique properties that make them very attractive as a renewable energy source. Of particular interest are semi-transparent cells, which have the potential to be integrated into building façades yet not completely block light. However, making organic cells transparent limits the metal electrode thickness to a few nanometres, drastically reducing its reflectivity and the device photon-harvesting capacity. Here, we propose and implement an ad hoc path for light-harvesting recovery to bring the photon-to-charge conversion up to almost 80% that of its opaque counterpart. We report semi-transparent PTB7:PC71BM cells that exhibit 30% visible light transmission and 5.6% power conversion efficiency. Non-periodic photonic crystals are used to trap near-infrared and near-ultraviolet photons. By modifying the layer structure it is possible to tune the device colour without significantly altering cell performance. [ABSTRACT FROM AUTHOR]

Abstract: We fabricated P3HT:PCBM bulk hetero-junction solar cells, where a 5nm layer of NiO sputtered on top of ITO is used as an effective electron blocking layer. All the steps involving the processing of the organic materials were performed in ambient air. Under 1 sun of AM1.5G illumination such NiO cells exhibited a power conversion efficiency of 3.3% compared to 3.1% exhibited by a PEDOT:PSS cell fabricated under similar conditions. We observed that for the NiO cell processing in air was not detrimental to the ulterior performance of the cell, which in ambient air degraded with a time constant of 303h. On the contrary, the PEDOT:PSS cell degraded very rapidly and the loss in efficiency was shown to be 29 times faster when compared to that of the NiO cell. [ABSTRACT FROM AUTHOR]

The combined optical management of an optical cavity and a photonic crystal, reported by Jordi Martorell and co‐workers in article number 1400614, enhances the performance of semitransparent organic solar cells to achieve power conversion efficiencies comparable to the ones seen in the corresponding opaque cells. This result makes it possible to create window‐integrated photovoltaic solutions without compromising power conversion. [ABSTRACT FROM AUTHOR]