Despite the recent unprecedented increase in the power conversion efficiencies (PCEs) of small-area devices (≤0.1 cm ), the PCEs deteriorate drastically for PSCs of larger areas because of the incomplete film coverage caused by the dewetting of the hydrophilic perovskite precursor solutions on the hydrophobic organic charge-transport layers (CTLs). Here, an innovative method of fabricating scalable PSCs on all types of organic CTLs is reported. By introducing an amphiphilic conjugated polyelectrolyte as an interfacial compatibilizer, fabricating uniform perovskite films on large-area substrates (18.4 cm ) and PSCs with the total active area of 6 cm (1 cm × 6 unit cells) via a single-turn solution process is successfully demonstrated. All of the unit cells exhibit highly uniform PCEs of 16.1 ± 0.9% (best PCE of 17%), which is the highest value for printable PSCs with a total active area larger than 1 cm .

Simultaneously achieving high optical transparency and excellent charge mobility in semiconducting polymers has presented a challenge for the application of these materials in future "flexible" and "transparent" electronics (FTEs). Here, by blending only a small amount (∼15 wt %) of a diketopyrrolopyrrole-based semiconducting polymer (DPP2T) into an inert polystyrene (PS) matrix, we introduce a polymer blend system that demonstrates both high field-effect transistor (FET) mobility and excellent optical transparency that approaches 100%. We discover that in a PS matrix, DPP2T forms a web-like, continuously connected nanonetwork that spreads throughout the thin film and provides highly efficient 2D charge pathways through extended intrachain conjugation. The remarkable physical properties achieved using our approach enable us to develop prototype high-performance FTE devices, including colorless all-polymer FET arrays and fully transparent FET-integrated polymer light-emitting diodes.semiconducting polymer | organic electronics | flexible and transparent device | polymer blend | charge transport O ptically transparent and mechanically flexible circuitries have long been desired for next-generation electronics requiring unprecedented features, such as "see-through" visibility, deformability, and even skin-attachable functionality for health care systems (1-3). This new paradigm for electronic applications has motivated researchers to eagerly pursue new innovative semiconducting materials, and one promising candidate is the class of materials called semiconducting conjugated polymers (4). Their unique benefits, including mechanical flexibility, light weight, and processing advantages based on high-throughput fabrication processes using solution-printing technologies, have accelerated the development of these materials as key building blocks for next-generation ubiquitous systems (2, 5, 6). Nevertheless, these materials still cannot fulfill the ultimate requirements for future "flexible" and "transparent" electronics (FTEs). Together with their inferior charge-carrier mobility because of conformational and energetic disorder (7), their high light absorption in the visible range, which is inherent to this class of materials (absorption coefficient ∼10 5 cm −1 ) (8), makes it difficult to apply these materials in FTEs. Indeed, despite extensive investigations seeking a suitable model system for FTEs by varying the polymer-structure design and the processing techniques used, the simultaneous achievement of optical transparency and high mobility in semiconducting polymers remains a formidable challenge (9, 10).Among the various types of semiconducting polymers, lowbandgap polymers using the donor-acceptor (D-A) copolymerization scheme are promising candidate materials for FTE applications. These semiconducting copolymers usually exhibit much less absorption in the visible range compared with other typical midbandgap polymers because of their red-shifted π-π* absorption spectrum, which exhibits strong absorption in the ne...

Nucleation and growth processes can be effectively controlled in organic semiconductor films through a new concept of template-mediated molecular crystal seeds during the phase transition; the effective control of these processes ensures millimeter-scale crystal domains, as well as the performance of the resulting organic films with intrinsic hole mobility of 18 cm(2) V(-1) s(-1).

The origin of performance enhancements in p‐i‐n perovskite solar cells (PSCs) when incorporating low concentrations of the bulky cation 1‐naphthylmethylamine (NMA) are discussed. A 0.25 vol % addition of NMA increases the open circuit voltage (Voc) of methylammonium lead iodide (MAPbI3) PSCs from 1.06 to 1.16 V and their power conversion efficiency (PCE) from 18.7% to 20.1%. X‐ray photoelectron spectroscopy and low energy ion scattering data show NMA is located at grain surfaces, not the bulk. Scanning electron microscopy shows combining NMA addition with solvent assisted annealing creates large grains that span the active layer. Steady state and transient photoluminescence data show NMA suppresses non‐radiative recombination resulting from charge trapping, consistent with passivation of grain surfaces. Increasing the NMA concentration reduces device short‐circuit current density and PCE, also suppressing photoluminescence quenching at charge transport layers. Both Voc and PCE enhancements are observed when bulky cations (phenyl(ethyl/methyl)ammonium) are incorporated, but not smaller cations (Cs/MA)—indicating size is a key parameter. Finally, it demonstrates that NMA also enhances mixed iodide/bromide wide bandgap PSCs (Voc of 1.22 V with a 1.68 eV bandgap). The results demonstrate a facile approach to maximizing Voc and provide insights into morphological control and charge carrier dynamics induced by bulky cations in PSCs.

Printable organic sensors fabricated from solution-processed π-conjugated polymers (π-CPs) are promising candidates to detect volatile organic compounds (VOCs) due to the intriguing physical, chemical and electronic properties of π-CPs. These...