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Abstract The transition of polymer solar cells (PSCs) from laboratory‐scale unit cells to industrial‐scale modules requires the development of new p‐type polymers for high‐performance large‐area PSC modules based on environmentally friendly processes. Herein, a series of 1D/2A terpolymers (PBTPttBD) composed of benzo[1,2‐b:4,5‐b’]dithiophene (BDT‐F), thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (TPD‐TT), and benzo‐[1,2‐c:4,5‐c’]dithiophene‐4,8‐dione (BDD) is synthesized for nonhalogenated solvent processed PSC submodules. The optical, electrochemical, charge‐transport, and nano‐morphological properties of the PBTPttBD terpolymers are modulated by adjusting the molar ratio of the TPD‐TT and BDD components. PBTPttBD‐75:BTP‐eC11‐based PSC submodules, processed with o‐xylene, achieve a notable PCE of 11.57% over a 55 cm2 active area. This PCE value is among the highest reported using a nonhalogenated solvent over a 55 cm2 active area module. The optimized PSC submodule exhibits minimal cell‐to‐module loss, which can be attributed to the optimized crystallinity of the PBTPttBD‐75:BTP‐eC11 photoactive layer system and favorable film formation kinetics.

Realization of state‐of‐the art efficiencies in organic photovoltaics (OPV) generally relies on using toxic halogenated solution processing to arrive at the desired nanomorphology and optoelectronic responses, whereas the photovoltaic performance in nonhalogenated solution (NHS)‐based OPVs is yet nonsatisfactory, mainly related to the difficulty of morphological control. Herein, a conceptual approach of donor‐dispersed planar heterojunction (DD‐PHJ) for improving the regulation of phase morphology and photovoltaic behaviors in NHS‐processed OPVs is proposed, afforded by dispersing an ordered liquid crystal guest donor BTR‐Cl into the nonfullerene acceptor host with sequential film deposition. The combined investigation shows that the inclusion of BTR‐Cl plays a regulatory role in enhancing the crystallization, intermolecular donor/acceptor miscibility, and homogeneity in the donor–acceptor phase separation along vertical direction, which is conducive to improved charge transfer and reduced photovoltage loss. Of importance, the described DD‐PHJ approach is applicable to representative OPV material systems, leading to a champion efficiency of 18.21% in devices prepared with NHS. This work provides a promising prospect toward high‐efficiency and green solution‐processed OPV devices. [ABSTRACT FROM AUTHOR]

Hybrid solar cells with organic semiconductors and quantum dots (QDs) have witnessed great advance in the past few years. Nevertheless, the great majority of organic and QD hybrid solar cells generally employ halogenated solvents for the processing of organic hole‐transporting interlayers. Herein, the impact of solvents on the organic semiconductor material for hybird solar cells is systematically explored. The o‐xylene‐processed polythiophene delivers a champion photovoltaic performance of 8.7%, which is the record value for QD and poly(3‐hexylthiophene) (P3HT) hybrid solar cells. The morphology results reveal that P3HT films processed with o‐XY present the moderate morphology and characteristic length scales, enabling the high photovoltaic performance. Moreover, the relationships between solvents, molecular stacking, film morphology, and photovoltaic performance are built to offer the guideline of solvents screening for these hybrid solar cells. Moreover, the great superiority of nonhalogenated solvents in fabricating high‐performance optoelectronic devices with low hazards is demonstrated. [ABSTRACT FROM AUTHOR]

Single‐component organic solar cells (SCOSCs), which contain only one photoactive material in their active layers, promise many advantages with respect to the excellent device and morphological stabilities and a simplified film fabrication process. However, most of the high‐efficiency SCOSCs are fabricated by halogenated solvents. Herein, the eco‐friendly and highly efficient SCOSCs based on a conjugated block copolymer PBDB‐T‐b‐PYT with power conversion efficiencies (PCEs) of over 12% are developed by utilizing a series of halogen‐free processing solvents (including tetrahydrofuran, toluene, o‐xylene), being higher than those of the devices cast from halogenated solvents (including chloroform, chlorobenzene, 1,2‐dichlorobenzene). Impressively, by using o‐xylene as processing solvent for the PBDB‐T‐b‐PYT active layer, high and balanced charge transport properties, and well‐developed morphological features are observed, leading to a high PCE of 12.60%, which is the highest value among SCOSCs to date. Importantly, the non‐halogenated solvents‐processed devices exhibited better storage and operational stabilities as compared to the chloroform (CF)‐processed SCOSCs. More importantly, higher photovoltaic performance (over 12% PCEs) of the green‐solvent‐processed devices as compared with the CF‐processed devices fabricated by blade coating in ambient conditions are achieved, suggesting the promising prospects of SCOSCs toward industrial production, particularly being relevant for environmentally benign solvents. [ABSTRACT FROM AUTHOR]

Blade‐coating which is compatible with roll‐to‐roll (R2R) fabrication has been considered a promising technology for the large‐scale production of organic solar cells (OSCs). Despite the rapid increase in power conversion efficiency (PCE) of the devices, most processing solvents are still halogenated, which is a key issue that needs to be addressed urgently in commercialized manufacturing. In this work, targeted strategies are explored for the preparation of efficient OSCs via combining the nonhalogenated solvent toluene (TL) with blade‐coating. Based on the in situ UV–vis absorption, grazing‐incidence wide‐angle X‐ray scattering, and device performance measurements, the subtle relationship between processing solvents, film morphology, and properties is successfully established. The PM6:BTP‐eC9 blend film prepared by this strategy demonstrates higher crystallinity and smaller phase separation morphology, resulting in an outstanding PCE of 16.58% with low energy loss and high fill factor, which is higher than the CF‐based device (15.08%). Finally, the 1.00 cm2 device exhibits a high PCE of 14.82%, which is one of the highest values for OSCs prepared by blade‐coating based on TL solvent. This specific strategy combines blade‐coating with nonhalogenated solvent processing shows outstanding synergy in optimization of morphology, demonstrating excellent potential for the preparation of highly efficient large area OSCs. [ABSTRACT FROM AUTHOR]

Donor–acceptor (D–A) copolymer‐based polymer solar cells (PSCs) processed with nonhalogenated solvents exhibit relatively low power conversion efficiencies (PCE) due to undesirable morphological properties, including high aggregation and unfavorable orientation. Moreover, they show very poor long‐term stability owing to excessive molecular aggregation and unfavorable phase separation. Thus, novel p‐type polymers are required for high‐efficiency and long‐lived PSCs that can be processed in ecofriendly nonhalogenated solvents. Herein, a novel series of 1D/2A terpolymers (PBTPBD) composed of 4,8‐bis(5‐(2‐ethylhexyl)‐4‐fluorothiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene (BDT‐F), 1,3‐bis(thiophen‐2‐yl)‐5,7‐bis(2‐ethylhexyl)benzo‐[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione (BDD), and 1,3‐bis‐(4‐hexylthiophen‐2‐yl)‐5‐octyl‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (HT‐TPD) is synthesized and characterized for high‐efficiency and long‐lived PSCs. A PBTPBD‐50:IT‐4F blended film exhibits a favorable face‐on orientation and superior hole and electron mobility. Therefore, the corresponding PBTPBD‐50:IT‐4F PSC, processed with a nonhalogenated solvent, exhibits a high PCE of 13.64%, which is 13% higher than that of the related nonhalogenated solvent‐processed PSCs. Furthermore, the PBTPBD‐50:IT‐4F PSC maintains 82% of the initial PCE even after 204 days at 85 °C, which is the highest thermal stability achieved among PSCs processed with nonhalogenated solvents. The high‐efficiency and superior long‐term thermal stability of the PBTPBD‐50:IT‐4F PSC are attributed to the excellent miscibility of PBTPBD‐50 and IT‐4F and the suppression of the morphological changes in the photoactive layer. [ABSTRACT FROM AUTHOR]

Nonhalogenated ecofriendly solvents are an important asset to avoid costly safety precautions during the fabrication of organic solar cells by printing. Yet, in the past, the quest for suitable nontoxic solvents has widely used empirical approaches. Herein, a comprehensive solubility study is rolled out embracing Hansen solubility parameters (HSPs), tailoring of binary solvents and rational choices of solvent additives, identifying ecofriendly solvents or solvent combinations for the deposition of poly‐benzodithophene‐thienopyrroledione (PBDTTPD)/fullerene thin‐film blends. A particular challenge is the low polymer solubility even in common halogenated solvents. Following the HSPs, initially, a list of suitable solvent candidates is identified which are tested toward their applicability in solar cell fabrication. Among the shortlisted solvents, significant differences between p‐xylene and o‐xylene are observed, which can be compensated using solvent additives. The ecofriendly green solvent eucalyptol in combination with benzaldehyde and p‐anisaldehyde in a ternary solvent mixture gives rise to decent solar cell performances. Solar cells are produced with power conversion efficiencies matching those conventionally fabricated from state‐of‐the‐art halogenated solvents comprising chlorobenzene and chloronaphthalene. Notably, the Hansen solubility approach provides an initial choice of solvents, but comes to its limits in predicting the best micromorphology formation, or if solvents react with the organic semiconductors.

The remarkable advance of all‐polymer solar cells (all‐PSCs) achieved in the past decades is primarily powered by the innovation of polymer acceptors. However, most of high‐performance all‐PSCs are dominantly fabricated with halogenated solvents, which are detrimental to human bodies and the environment. Herein, eco‐friendly solvent‐processed all‐PSCs were developed, based on wide‐bandgap polymer poly[4,8‐bis(5‐(2‐ethylhexylthio)thiophen‐2‐yl)‐benzo‐[1,2‐b;4,5‐b']dithiophene‐alt‐2,5‐di(butyloctylthiophen‐2‐yl) ‐thiazolo[5,4‐d]thiazole] (PSTZ) as donor and newly synthesized narrow‐bandgap polymer 5,6‐dicyano‐2,1,3‐benzothiadiazole indacenodithiophene (DCNBT‐IDT) as acceptor. When processed with o‐xylene and THF, PSTZ : DCNBT‐IDT‐based all‐PSCs yielded remarkable power conversion efficiencies of 7.23 and 8.77 % with high short‐circuit currents of 12.94 and 14.12 mA cm−2, respectively. The results indicated that the utilization of an all‐polymer blend based on narrow polymer acceptor and compatible polymer donor is an effective strategy for advancing eco‐friendly solvent‐processed all‐PSCs. [ABSTRACT FROM AUTHOR]

Rapid developments in material design have led to significant breakthroughs in the power conversion efficiency (PCE) of all‐polymer solar cells (all‐PSCs) in recent years. However, most of these devices are processed using halogenated solvents. Here, nonhalogenated solvent o‐xylene (o‐XY)‐processed all‐PSCs based on PBDB‐T:PJ1 are studied. Interestingly, it is found that the efficiency of the all‐PSCs can be greatly improved to 14.34% by simply increasing the spin‐coating speed during device processing. Careful studies reveal that this improvement could be attributed to the stronger centrifugal force (resulting from a higher spin‐coating speed), shorten the film formation time, and inhibit the excessive aggregation of PJ1. Consequently, a blend film with more reasonable domain size is formed. Based on these findings, another polymer acceptor PJ2, which bears a similar backbone to PJ1 but contains an additional thiophene spacer, is designed. PJ2 exhibits a much weaker aggregation ability and is used as a compatibilizer to improve the miscibility between the PBDB‐T and PJ1. Eventually, PBDB‐T:PJ1:PJ2‐based ternary all‐PSCs with a best PCE of 14.28% but processed under more mild conditions are obtained. These results may provide guidelines for future industrial fabrication of large‐area all‐PSCs. [ABSTRACT FROM AUTHOR]

Polymer semiconductors hold tremendous potential for applications in flexible devices, which is however hindered by the fact that they are usually processed by halogenated solvents rather than environmentally more friendly solvents. An effective strategy to boost the solubility of high-performance polymer semiconductors in nonhalogenated solvents such as tetrahydrofuran (THF) by appending hydroxyl groups in the side chains is herein presented. The results show that hydroxyl groups, which can be easily incorporated into the side chains, can significantly improve the solubility of typical p- and n-types as well as ambipolar polymer semiconductors in THF. Meanwhile, the thin films of these polymer semiconductors from the respective THF solutions show high charge mobilities. With THF as the processing and developing solvents these polymer semiconductors with hydroxyl groups in the side chains can be well photopatterned in the presence of the photo-crosslinker, and the charge mobilities of the patterned thin films are mostly maintained by comparing with those of the respective pristine thin films. Notably, THF is successfully utilized as the processing and developing solvent to achieve high-density photopatterning with ≈82 000 device arrays cm -2 for polymer semiconductors in which hydroxyl groups are appended in the side chains., (© 2024 Wiley‐VCH GmbH.)

Lifecycle assessments suggest preventing halogenated solvents or solvent additives for environmentally friendly polymer solar cells. Thus, the active layers of polymer:fullerene bulk heterojunction solar cells based on poly{[4,8‐bis‐(2‐ethyl‐hexyl‐thiophene‐5‐yl)‐benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl]‐alt‐[2‐(20‐ethyl‐hexanoyl)‐thieno[3,4‐b]thiophen‐4,6‐diyl]} (PBDTTT‐CT) and the fullerene derivative [6,6]‐phenyl‐C70‐butyric acid methyl ester (PC70BM) are cast from m‐xylene solutions. Ortho‐vanilline is used as a nonhazardous and nontoxic solvent additive. Completed photovoltaic devices are subjected to accelerated laboratory weathering tests. Photovoltaic parameters are periodically obtained from current–voltage recordings of the solar cells twice an hour under well‐defined aging conditions following the International Summit on Organic Photovoltaic Stability (ISOS) protocols. An analysis of aging kinetics reveals the superposition of two individual degradation mechanisms, of which one is assigned to continued intermixing and the other one to the formation of a blocking layer by interfacial segregation. [ABSTRACT FROM AUTHOR]

Abstract Significant progress has been made in nonfullerene small molecule acceptors (NF‐SMAs) that leads to a consistent increase of power conversion efficiency (PCE) of nonfullerene organic solar cells (NF‐OSCs). To achieve better compatibility with high‐performance NF‐SMAs, the direction of molecular design for donor polymers is toward wide bandgap (WBG), tailored properties, and preferentially ecofriendly processability for device fabrication. Here, a weak acceptor unit, methyl 2,5‐dibromo‐4‐fluorothiophene‐3‐carboxylate (FE‐T), is synthesized and copolymerized with benzo[1,2‐b:4,5‐b′]dithiophene (BDT) to afford a series of nonhalogenated solvent processable WBG polymers P1‐P3 with a distinct side chain on FE‐T. The incorporation of FE‐T leads to polymers with a deep highest occupied molecular orbital (HOMO) level of −5.60−5.70 eV, a complementary absorption to NF‐SMAs, and a planar molecular conformation. When combined with the narrow bandgap acceptor ITIC‐Th, the solar cell based on P1 with the shortest methyl chain on FE‐T achieves a PCE of 11.39% with a large Voc of 1.01 V and a Jsc of 17.89 mA cm−2. Moreover, a PCE of 12.11% is attained for ternary cells based on WBG P1, narrow bandgap PTB7‐Th, and acceptor IEICO‐4F. These results demonstrate that the new FE‐T is a highly promising acceptor unit to construct WBG polymers for efficient NF‐OSCs.

All current highest efficiency perovskite solar cells (PSCs) use highly toxic, halogenated solvents, such as chlorobenzene (CB) or toluene (TLN), in an antisolvent step or as solvent for the hole transporter material (HTM). A more environmentally friendly antisolvent is highly desirable for decreasing chronic health risk. Here, the efficacy of anisole (ANS), as a greener antisolvent for highest efficiency PSCs, is investigated. The fabrication inside and outside of the glovebox showing high power conversion efficiencies of 19.9% and 15.5%, respectively. Importantly, a fully nonhalogenated solvent system is demonstrated where ANS is used as both the antisolvent and the solvent for the HTM. With this, state-of-the-art efficiencies close to 20.5%, the highest to date without using toxic CB or TLN, are reached. Through scanning electron microscopy, UV-vis, photoluminescence, and X-ray diffraction, it is shown that ANS results in similar mixed-ion perovskite films under glovebox atmosphere as CB and TLN. This underlines that ANS is indeed a viable green solvent system for PSCs and should urgently be adopted by labs and companies to avoid systematic health risks for researchers and employees. [ABSTRACT FROM AUTHOR]

A wide-bandgap polymer, (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2- b:4,5- b′]dithiophene))- alt-(2,5-(methyl thiophene carboxylate))]) (3MT-Th), is synthesized to obtain a complementary broad range absorption when harmonized with 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3- d:2′,3′- d′]- s-indaceno[1,2- b:5,6- b′]dithiophene (ITIC). The synthesized regiorandom 3MT-Th polymer shows good solubility in nonhalogenated solvents. A film of 3MT-Th:ITIC can be employed for forming an active layer in a polymer solar cell (PSC), with the blend solution containing toluene with 0.25% diphenylether as a nonhalogenated additive. The corresponding PSC devices display a power conversion efficiency of 9.73%. Moreover, the 3MT-Th-based PSCs exhibit excellent shelf-life time of over 1000 h and are operationally stable under continuous light illumination. Therefore, methyl thiophene-3-carboxylate in 3MT-Th is a promising new accepting unit for constructing p-type polymers used for high-performance nonfullerene-type PSCs. [ABSTRACT FROM AUTHOR]

Dispersive liquid-liquid microextraction (DLLME) combined with gas chromatography and mass spectrometry (GC-MS) was applied to the determination of five organophosphorous pesticides (OPPs) in water samples. The analytes included in this study were prophos, diazinon, chlorpyrifos methyl, fenchlorphos, and chlorpyrifos. The use of nonhalogenated solvents (cyclohexane, heptane, and octane) as extraction solvents was investigated using acetone, acetonitrile, or methanol, as dispersion solvents. The combination of less polar dispersion solvents (1-propanol and 2-propanol) and nonhalogenated extraction solvents was also studied in dispersive liquid-liquid microextraction for the first time. Several experimental conditions were tested (nature and volume of extraction solvents, nature and volume of dispersion solvents, salting-out effect) and the corresponding enrichment factors and recoveries were evaluated. The best microextraction condition was obtained using 50 μL of cyclohexane and 0.3 mL of 1-propanol. The detection and quantification limits were in the low ppt range, with values between 3.3-8.0 ng/L and 11.0-26.6 ng/L, respectively. Relative standard deviations were between 6.6 and 13.1% for a fortification level of 500 ng/L. At the same fortification level, the relative recoveries (RR) of Alvito's dam water, Judeu's river water, and well water samples were in the range of 50.3-97.1%. [ABSTRACT FROM AUTHOR]

Benefiting from low cost and simple synthesis, polythiophene (PT) derivatives are one of the most popular donor materials for organic solar cells (OSCs). However, polythiophene-based OSCs still suffer from inferior power conversion efficiency (PCE) than those based on donor-acceptor (D-A)-type conjugated polymers. Herein, a fluorinated polythiophene derivative, namely P4T2F-HD, is introduced to modulate the miscibility and morphology of the bulk heterojunction (BHJ)-active layer, leading to a significant improvement of the OSC performance. The Flory-Huggins interaction parameters calculated from the surface energy and differential scanning calorimetry results suggest that P4T2F-HD shows moderate miscibility with the popular nonfullerene acceptor Y6-BO (2,2'-((2Z,2'Z)-((12,13-bis(2-butyloctyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2',3':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile), while poly(3-hexylthiophene) (P3HT) is very miscible with Y6-BO. As a result, the P4T2F-HD case forms desired nanoscale phase separation in the BHJ film while the P3HT case forms a completely mixed BHJ film, as revealed by transmission electron microscopy (TEM) and grazing-incidence wide-angle X-ray scattering (GIWAXS). By optimizing the cathode interface and the morphology of the P4T2F-HD:Y6-BO films processed from nonhalogenated solvents, a new record PCE of 13.65% for polythiophene-based OSCs is demonstrated. This work highlights the importance of controlling D/A interactions for achieving desired morphology and also demonstrates a promising OSC system for potential cost-effective organic photovoltaics., (© 2021 Wiley-VCH GmbH.)

Significant progress has been made in nonfullerene small molecule acceptors (NF‐SMAs) that leads to a consistent increase of power conversion efficiency (PCE) of nonfullerene organic solar cells (NF‐OSCs). To achieve better compatibility with high‐performance NF‐SMAs, the direction of molecular design for donor polymers is toward wide bandgap (WBG), tailored properties, and preferentially ecofriendly processability for device fabrication. Here, a weak acceptor unit, methyl 2,5‐dibromo‐4‐fluorothiophene‐3‐carboxylate (FE‐T), is synthesized and copolymerized with benzo[1,2‐b:4,5‐b′]dithiophene (BDT) to afford a series of nonhalogenated solvent processable WBG polymers P1‐P3 with a distinct side chain on FE‐T. The incorporation of FE‐T leads to polymers with a deep highest occupied molecular orbital (HOMO) level of −5.60−5.70 eV, a complementary absorption to NF‐SMAs, and a planar molecular conformation. When combined with the narrow bandgap acceptor ITIC‐Th, the solar cell based on P1 with the shortest methyl chain on FE‐T achieves a PCE of 11.39% with a large Voc of 1.01 V and a Jsc of 17.89 mA cm−2. Moreover, a PCE of 12.11% is attained for ternary cells based on WBG P1, narrow bandgap PTB7‐Th, and acceptor IEICO‐4F. These results demonstrate that the new FE‐T is a highly promising acceptor unit to construct WBG polymers for efficient NF‐OSCs. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) are one of the most promising cost-effective options for utilizing solar energy, and, while the field of OSCs has progressed rapidly in device performance in the past few years, the stability of nonfullerene OSCs has received less attention. Developing devices with both high performance and long-term stability remains challenging, particularly if the material choice is restricted by roll-to-roll and benign solvent processing requirements and desirable mechanical durability. Building upon the ink (toluene:FTAZ:IT-M) that broke the 10% benchmark when blade-coated in air, a second donor material (PBDB-T) is introduced to stabilize and enhance performance with power conversion efficiency over 13% while keeping toluene as the solvent. More importantly, the ternary OSCs exhibit excellent thermal stability and storage stability while retaining high ductility. The excellent performance and stability are mainly attributed to the inhibition of the crystallization of nonfullerene small-molecular acceptors (SMAs) by introducing a stiff donor that also shows low miscibility with the nonfullerene SMA and a slightly higher highest occupied molecular orbital (HOMO) than the host polymer. The study indicates that improved stability and performance can be achieved in a synergistic way without significant embrittlement, which will accelerate the future development and application of nonfullerene OSCs., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In article number 1700566, Min Ju Cho, Dong Hoon Choi, and co‐workers report a new conjugated widebandgap donor polymer, 3MT‐Th, harmonized with an ITIC acceptor to enable the production of a polymer solar cell (PSC) with high efficiency of 9.73% under eco‐friendly conditions using a non‐halogenated solvent. This PSC also exhibits excellent shelf‐life stability in air and good operational stability under continuous light illumination. [ABSTRACT FROM AUTHOR]

The commercialization of nonfullerene organic solar cells (OSCs) critically relies on the response under typical operating conditions (for instance, temperature and humidity) and the ability of scale-up. Despite the rapid increase in power conversion efficiency (PCE) of spin-coated devices fabricated in a protective atmosphere, the efficiencies of printed nonfullerene OSC devices by blade coating are still lower than 6%. This slow progress significantly limits the practical printing of high-performance nonfullerene OSCs. Here, a new and relatively stable nonfullerene combination is introduced by pairing the nonfluorinated acceptor IT-M with the polymeric donor FTAZ. Over 12% efficiency can be achieved in spin-coated FTAZ:IT-M devices using a single halogen-free solvent. More importantly, chlorine-free, blade coating of FTAZ:IT-M in air is able to yield a PCE of nearly 11% despite a humidity of ≈50%. X-ray scattering results reveal that large π-π coherence length, high degree of face-on orientation with respect to the substrate, and small domain spacing of ≈20 nm are closely correlated with such high device performance. The material system and approach yield the highest reported performance for nonfullerene OSC devices by a coating technique approximating scalable fabrication methods and hold great promise for the development of low-cost, low-toxicity, and high-efficiency OSCs by high-throughput production., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)