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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]

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]

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]

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]

Abstract Perovskite solar cells have shown an impressive performance evolution during the last years. This technology has been mostly tested under laboratory conditions using small area devices. In this work, the outdoor photovoltaic performance of perovskite solar cells was evaluated under real tropical weather conditions. Specifically, two perovskite modules with active area of 17 and 50 cm2 were fabricated, encapsulated and tested. Taking a commercial silicon panel as reference, both technologies were evaluated for 500 h correlating the in-situ I-V measurements with atmospheric variables measured every minute during the light hours. To obtain the performance and the average outdoor efficiency of devices, we proposed a new adapted methodology based on the standard IEC 61853-1, showing the photovoltaic parameters performance through maps, to graphically visualize their behavior in a broad range of atmospheric conditions. Additionally, we demonstrated that the power delivery and short circuit current of both technologies correlate linearly with the atmospheric variables. Moreover, the open circuit voltage of perovskite technology exhibited a nonlinear behavior and an improved performance with temperature at high irradiance regimes. This work presents reliable information concerning perovskite solar technology performance under real outdoor operation conditions, being this crucial to identify competitive advantages of this technology and the aspects to be improved. Graphical abstract fx1 Highlights • Continuous perovskite solar cells monitoring under outdoor conditions. • New adapted methodology to evaluate perovskite modules. • Stable perovskite modules up to 500 h under real operation conditions. [ABSTRACT FROM AUTHOR]

Development of transparent electronics has been hindered by the lack of stable p-type transparent conductive electrodes. Herein we report the fabrication of p-type copper sulfide thin films (Cu x S) used for the first time as semitransparent electrode used as an example in inverted-planar perovskite solar cells (PSCs). The resulting hole-transporting-material-free and indium-tin-oxide-free (ITO-free) device showed an unprecedented 5.9% efficiency (PCE). Morphological, structural and optoelectronic analysis of the Cu x S films were accomplished to correlate the photovoltaic behavior of the obtained PSCs. In particular, covellite (CuS) and digenite (Cu 1.8 S) crystal phases were identified in the resulting Cu x S film. The p-type Cu x S semitransparent electrode exhibited high 1094 S cm −1 electrical conductivity comparable to state-of-the-art transparent conductive electrodes (TCE). Although the Cu x S electrode exhibits a relatively low bandgap around 2.7 eV, the spectral response of the devices demonstrates that the related optical loss happens just in the blue and UV region of the visible spectrum leading to a reduction of the photocurrent below 10%. On the other hand, surface photovoltage analysis of the grown perovskite indicates that the Cu x S electrode induces an optimal band alignment in the perovskite surface while trap states were favored by using Cu x S regarding ITO. These results suggest that photovoltaic parameters of Cu x S-based PSCs can be still improved by a better control of perovskite growing. Finally, material cost per square meter (US$/m2) was estimated for Cu x S electrodes and an impressive reduction of 77.6% was observed compared to commercial ITO. These results highlight the potential application of Cu x S film as low-cost, non-toxic and scalable p-type semitransparent electrode in PSCs and other optoelectronic devices. [ABSTRACT FROM AUTHOR]