PSC-efficiencies have increased with intensive effort on novel materials synthesis, film-morphology engineering, and interface control, and the state-of-the-art PSCs have eventually produced a high power conversion efficiency (PCE) of over 15%. [9][10][11][12][13][14][15][16][17][18][19][20][21] For example, Zou et al. reported a newly synthesized nonfullerene acceptor (NFA), Y6, having an electron-deficient-core-based fused ring with a benzothiadiazole unit, and the resulting single-junction PSCs based on PM6:Y6 BHJ showed an excellent efficiency of 15.7% and a certified PCE of 14.9%. [20] In addition, Hou and co-workers recently reported a series of copolymers, and in particular, the copolymer T1 (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)-benzo[1,2-b:4,5-b′] dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′] dithiophene-4,8-dione)] (PBDB-TF) = 0.8 and PTO2 = 0.2) produced the bestefficiency of 15.1% and certified PCE of 14.6% in PSCs using 3,9-bis(2-methylene-((3-(1,1-dicyanomethylene)-6,7difluoro)-indanone))-5,5,11,11-tetrakis(4hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′] dithiophene (IT-4F) acceptor. [21] One of the representative routes to further enhance PSCefficiency is broadening the absorption bandwidth of the active film for better sunlight absorption. [21][22][23] To this end, the ternary The record efficiency of the state-of-the-art polymer solar cells (PSCs) is rapidly increasing, due to the discovery of high-performance photoactive donor and acceptor materials. However, strong questions remain as to whether such high-efficiency PSCs can be produced by scalable processes. This paper reports a high power conversion efficiency (PCE) of 13.5% achieved with single-junction ternary PSCs based on PTB7-Th, PC 71 BM, and COi8DFIC fabricated by slot-die coating, which shows the highest PCE ever reported in PSCs fabricated by a scalable process. To understand the origin of the high performance of the slot-die coated device, slot-die coated photoactive films and devices are systematically investigated. These results indicate that the good performance of the slot-die PSCs can be due to a favorable moleculestructure and film-morphology change by introducing 1,8-diiodooctane and heat treatment, which can lead to improved charge transport with reduced carrier recombination. The optimized condition is then used for the fabrication of large-area modules and also for roll-to-roll fabrication. The slot-die coated module with 30 cm 2 active-area and roll-to-roll produced flexible PSC has shown 8.6% and 9.6%, respectively. These efficiencies are the highest in each category and demonstrate the strong potential of the slot-die coated ternary system for commercial applications. Photovoltaic DevicesThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.Over the past few decades, solution-processed bulk-heterojunction (BHJ) polymer solar cells (PSCs) have continued to demonstrate their potential as a high-ef...

The concurrent enhancement of the short-circuit current (JSC) and open-circuit voltage (VOC) is a key problem in the preparation of efficient organic solar cells (OSCs). In this paper, we report...

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.

With the advent of 5G wireless and Internet of Things technologies, flexible and stretchable printed circuit boards (PCBs) should be designed to address all the specifications necessary to receive signal transmissions, maintaining the signal integrity, and providing electrical connections. Here, we propose a silver nanoparticle (AgNP)/silver nanowire (AgNW) hybrid conductor and high-quality microprinting technology for fabricating flexible and stretchable PCBs in high-performance 5G wireless communication. A simple and low-cost reverse offset printing technique using a commercial adhesive hand-roller was adapted to ensure high-resolution and excellent pattern quality. The AgNP/ AgNW micropatterns were fabricated in various line widths, from 5 μm to 5 mm. They exhibited excellent pattern qualities, such as fine line spacing, clear edge definition and outstanding pattern uniformity. After annealing via intense pulsed light irradiation, they showed outstanding electrical resistivity (15.7 μΩ cm). Moreover, they could withstand stretching up to a strain of 90% with a small change in resistance. As a demonstration of their practical application, the AgNP/AgNW micropatterns were used to fabricate 5G communication antennas that exhibited excellent wireless signal processing at operating frequencies in the C-band (4−8 GHz). Finally, a wearable sensor fabricated with these AgNP/ AgNW micropatterns could successfully detected fine finger movements in real time with excellent sensitivity.

Copper nanowires (CuNWs) possess key characteristics for realizing flexible transparent electronics. High-quality CuNW micropatterns with high resolution and uniform thickness are required to realize integrated transparent electronic devices. However, patterning high-aspect-ratio CuNWs is challenging because of their long length, exceeding the target pattern dimension. This work reports a novel reverse-offset printing technology that enables the sub-10 μm high-resolution micropatterning of CuNW transparent conducting electrodes (TCEs). The CuNW ink for reverse-offset printing was formulated to control viscoelasticity, cohesive force, and adhesion by adjusting the ligands, solvents, surface energy modifiers, and leveling additives. An inexpensive commercial adhesive handroller achieved a simple, fast, and scalable micropatterning of CuNW TCEs. Easy production of high-quality CuNW micropatterns with various curvatures and shapes was possible, regardless of the printing direction. The reverse-offset-printed CuNW micropatterns exhibited a minimum of 7 μm line width and excellent pattern qualities such as fine line spacing, sharp edge definition, and outstanding pattern uniformity. In addition, they exhibited excellent sheet resistance, high optical transparency, outstanding mechanical durability, and long-term stability. Flexible light-emitting diode (LED) circuits, transparent heaters, and organic LEDs (OLEDs) can be fabricated using high-resolution reverse-offset-printed CuNW micropatterns for applications in flexible transparent electronic devices.