The first demonstration of entirely roll-to-roll fabricated perovskite solar cell modules under ambient room conditions

XRD of printed perovskite Device performance data of roll-to-roll fabricated perovskite solar cells and a modul

Toward a Sociology of Emotion

Seven conjugated copolymers, based on dithienylbenzothiadiazole and benzene, have been synthesized with side chains placed in different position along the conjugated backbone. An additional polymer with a small modification of the investigated backbone was also included in the study. Alkoxy and alkyl side chains were considered, depending on the aromatic ring they were anchored to. Our goal was to perform an extensive study, by evaluating the possible anchoring positions of the same backbone, in order to demonstrate the huge influence of the position of side chains on a well performing polymer backbone for polymer solar cells. All the polymers were roll slot die coated under ambient conditions on flexible ITO-free plastic substrates to give inverted polymer solar cell devices with an upscaled active area of 1 cm². The best characteristics were found for the polymer carrying alkoxy side chains on the benzene ring where power conversion efficiencies of up to 3.6% were achieved. All studied materials were prepared with an objective of low-cost starting materials, simple synthesis, and simple processing conditions which was most successful for the polymer <b>P5</b>. The polymer <b>P7</b> containing fluorine atoms showed excellent performance under constant illumination and high temperature (exhibiting stable photovoltaic properties even after 670 h under conditions similar to ISOS-L-2 lifetime protocol). This makes <b>P7</b> a good candidate for further upscaling and device optimization. The photovoltaic performance results were corroborated with full optical and morphological characterization of the conjugated polymers. We conclude that the determination of the best anchoring position for the side chains is the most rational starting point for the optimization of a polymer with a potential for large-scale fabrication of polymer solar cells

Toward Rollable Printed Perovskite Solar Cells for Deployment in Low-Earth Orbit Space Applications

The thin physical profile of perovskite-based solar cells (PSCs) fabricated on flexible substrates provides the prospect of a disruptive increase in specific power (power-to-mass ratio), an important figure-of-merit for solar cells to be used in space applications. In contrast to recent reports on space applications of PSCs which focus on rigid glass-based devices, in this work we investigate the suitability of flexible PSCs for low-earth orbit (LEO) applications, where the perovskite layer in the PSCs was prepared using either a Ruddlesden–Popper precursor composition (BA2MA3Pb4I13; BA = butylammonium, MA = methylammonium) or a mixed-cation precursor composition (Cs0.05FA0.81MA0.14Pb2.55Br0.45; FA = formamidinium). The flexible PSC devices display a tolerance to high-energy proton (14 MeV) and electron (>1 MeV) radiation comparable with, or superior to, equivalent glass-based PSC devices. The photovoltaic performance of the PSCs is found to be significantly less dependent on angle-of-incidence than GaAs-based triple-junction solar cells commonly used for space applications. Results from a preliminary test of the robustness of the perovskite film when subjected to LEO-like thermal environments are also reported. In addition, a unique deployment concept integrating printed flexible solar cells with titanium–nickel based shape memory alloy ribbons is presented for thermally actuated deployment of flexible solar cells from a rolled state

Toward Rollable Printed Perovskite Solar Cells for Deployment in Low-Earth Orbit Space Applications

The thin physical profile of perovskite-based solar cells (PSCs) fabricated on flexible substrates provides the prospect of a disruptive increase in specific power (power-to-mass ratio), an important figure-of-merit for solar cells to be used in space applications. In contrast to recent reports on space applications of PSCs which focus on rigid glass-based devices, in this work we investigate the suitability of flexible PSCs for low-earth orbit (LEO) applications, where the perovskite layer in the PSCs was prepared using either a Ruddlesden–Popper precursor composition (BA2MA3Pb4I13; BA = butylammonium, MA = methylammonium) or a mixed-cation precursor composition (Cs0.05FA0.81MA0.14Pb2.55Br0.45; FA = formamidinium). The flexible PSC devices display a tolerance to high-energy proton (14 MeV) and electron (>1 MeV) radiation comparable with, or superior to, equivalent glass-based PSC devices. The photovoltaic performance of the PSCs is found to be significantly less dependent on angle-of-incidence than GaAs-based triple-junction solar cells commonly used for space applications. Results from a preliminary test of the robustness of the perovskite film when subjected to LEO-like thermal environments are also reported. In addition, a unique deployment concept integrating printed flexible solar cells with titanium–nickel based shape memory alloy ribbons is presented for thermally actuated deployment of flexible solar cells from a rolled state

Beyond Fullerenes: Indacenodithiophene-Based Organic Charge-Transport Layer toward Upscaling of Low-Cost Perovskite Solar Cells

Phenyl-C₆₁-butyric acid methyl ester (PCBM) is universally used as the electron-transport layer (ETL) in the low-cost inverted planar structure of perovskite solar cells (PeSCs). PCBM brings tremendous challenges in upscaling of PeSCs using industry-relevant methods due to its aggregation behavior, which undermines the power conversion efficiency and stability. Herein, we highlight these, seldom reported, challenges with PCBM. Furthermore, we investigate the potential of nonfullerene indacenodithiophene (IDT)-based molecules by employing a commercially available variant, 3,9-bis­(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis­(4-hexylphenyl)-dithieno­[2,3-<i>d</i>:2′,3′-<i>d</i>′]-<i>s</i>-indaceno­[1,2-<i>b</i>:5,6-<i>b</i>′] dithiophene (ITIC), as a PCBM replacement in ambient-processed PeSCs. Films fabrication by laboratory-based spin-coating and industry-relevant slot-die coating methods are compared. Although similar power-conversion efficiencies are achieved with both types of ETL in a simple device structure fabricated by spin-coating, the nanofibriller morphology of ITIC compared to the aggregated morphology of PCBM films enables improved mechanical integrity and stability of ITIC devices. Upon slot-die coating, the aggregation of PCBM is exacerbated, leading to significantly lower power-conversion efficiency of devices than spin-coated PCBM as well as slot-die-coated ITIC devices. Our results clearly indicate that IDT-based molecules have great potential as an ETL in PeSCs, offering superior properties and upscaling compatibility than PCBM. Thus, we present a short summary of recently emerged nonfullerene IDT-based molecules from the field of organic solar cells and discuss their scope in PeSCs as electron or hole-transport layer