Improving the long-term stability of perovskite solar cells is critical to the deployment of this technology. Despite the great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters reported. It is therefore challenging to reproduce and compare results and thereby develop a deep understanding of degradation mechanisms. Here, we report a consensus between researchers in the field on procedures for testing perovskite solar cell stability, which are based on the International Summit on Organic Photovoltaic Stability (ISOS) protocols. We propose additional procedures to account for properties specific to PSCs such as ion redistribution under electric fields, reversible degradation and to distinguish ambient-induced degradation from other stress factors. These protocols are not intended as a replacement of the existing qualification standards, but rather they aim to unify the stability assessment and to understand failure modes. Finally, we identify key procedural information which we suggest reporting in publications to improve reproducibility and enable large data set analysis.

T. (2017). One-step deposition by slot-die coating of mixed lead halide perovskite for photovoltaic applications. Solar Energy Materials and Solar Cells, 159,[362][363][364][365][366][367][368][369] http://dx. AbstractRecent advances in the performance and stability of lead halide perovskite solar cells announce a promising future for this technology. As the understanding of lab scale device fabrication progresses technology developments in the area of up-scaling are required to demonstrate their viability on an industrial and pre-commercial scale. These developments include replacing slow spin coated deposition techniques with continuous roll to roll compatible slot-die methods. In this work we demonstrate the suitability of a one-step slot-die coating method for the deposition of lead halide perovskite layers, in particular for infiltration into a mesoporous titania scaffold. Appropriate crystallisation dynamics of the perovskite are achieved by careful control of the substrate temperature in combination with a post-processed rapid air knife application. We show that devices fully processed in air using this method deliver a photovoltaic conversion efficiency up to 9.2% , this is comparable to those manufactured using a spin coating process.

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mesoporous stack-titania (m-TiO 2 ), zirconia (ZrO 2 ), carbon (C)-is printable, C-PSCs are ideal for large scale production and, interestingly, some features that prevent degradation, i.e., lack of metal cathode [9] and organic HTM, [10] are also responsible for the simpler manufacturing process, paving the way for C-PSCs to move quickly from the lab to the market. This module architecture not only uses low-cost materials but can be produced by equipment that has a very low-capital cost thus reducing the barrier to commercialization of perovskite modules. Constraining the grain growth of the perovskite completely within the three mesoporous structures enables crystallization of the perovskite over large areas without the need for dynamic drying [11,12] to mimic the spin coating process. [13] There have been some reports demonstrating that C-PSC modules can be produced by screen printing, via registration of the overlapping layers, and can deliver between 10 and 11% power conversion efficiency (PCE) on 10 × 10 cm 2 substrates, with active areas ranging from 47.6 [7,14] to 70 cm 2 , [15] and, in particular, showing over 1 year stability under illumination, as reported by Grancini et al. [7] These results for C-PSC modules are even more remarkable, considering that modules with comparable active areas (>45 cm 2 ) and different device architecture, yielded respectively 12.6% PCE on 50.6 cm 2 (FTO/c-TiO 2 /graphene+m-TiO 2 / GO-Li/perovskite/spiro-OMeTAD/Au), [16] 8.7% PCE on 60 cm 2 (ITO/PEDOT:PSS/perovskite/PCBM/Au), [17] and 4.3% PCE on 100 cm 2 (FTO/c-TiO 2 /m-TiO 2 /perovskite/spiro-OMeTAD/ Au) [11] ; moreover, the record for PSC modules overall is Microquanta's 16% PCE [18,19] on just 16.29 cm 2 aperture area (active area + dead area for interconnections).Upscaling C-PSC manufacture from 10 × 10 cm 2 to larger substrate dimensions, e.g., A4 size as in our case, is far from trivial. Spraying the TiO 2 blocking layer (BL) at temperatures as high as 300 °C causes the large substrates to crack in the worst case or to bend, compromising the thickness homogeneity over the substrate of the printed layers, mostly and more crucially for the thinnest of the three, the sub-micrometric m-TiO 2 . Any change in the layers' thickness across the substrate can affect the performance of individual cells constituting the module Perovskite solar cells based on an all printable mesoporous stack, made of overlapping titania, zirconia, and carbon layers, represent a promising device architecture for both simple, low-cost manufacture, and outstanding stability. Here a breakthrough in the upscaling of this technology is reported: Screen printed modules on A4 sized conductive glass substrates, delivering power conversion efficiency (PCE) ranging from 3 to 5% at 1 sun on an unprecedented 198 cm 2 active area. An increase in the PCE, due to higher V OC and fill factor, is demonstrated by patterning the TiO 2 blocking layer. Furthermore, an unexpected increase of the performance is observed over time, while storing the modules in the dark,...