Understanding asymmetric switching times in accumulation mode organic electrochemical transistors.

Understanding the factors underpinning device switching times is crucial for the implementation of organic electrochemical transistors in neuromorphic computing, bioelectronics and real-time sensing applications. Existing models of device operation cannot explain the experimental observations that turn-off times are generally much faster than turn-on times in accumulation mode organic electrochemical transistors. Here, using operando optical microscopy, we image the local doping level of the transistor channel and show that turn-on occurs in two stages-propagation of a doping front, followed by uniform doping-while turn-off occurs in one stage.

Multifunctional Hybrid Interfacial Layers for High-Performance Inverted Perovskite Solar Cells.

Challenges remain hindering the performance and stability of inverted perovskite solar cells (PSCs), particularly for the nonstable interface between lead halide perovskite and charge extraction metal oxide layer. Herein, a simple yet scalable interfacial strategy to facilitate the assemble of high-performance inverted PSCs and scale-up modules is reported. The hybrid interfacial layer containing self-assembly triphenylamine and conjugated poly(arylamine) simultaneously improves the chemical stability, charge extraction, and energy level alignment of hole-selective interface, meanwhile promoting perovskite crystallization.

Asymmetric electron acceptor enables highly luminescent organic solar cells with certified efficiency over 18.

Enhancing the luminescence property without sacrificing the charge collection is one key to high-performance organic solar cells (OSCs), while limited by the severe non-radiative charge recombination. Here, we demonstrate efficient OSCs with high luminescence via the design and synthesis of an asymmetric non-fullerene acceptor, BO-5Cl. Blending BO-5Cl with the PM6 donor leads to a record-high electroluminescence external quantum efficiency of 0.

Molecular insights of exceptionally photostable electron acceptors for organic photovoltaics.

Photo-degradation of organic semiconductors remains as an obstacle preventing their durable practice in optoelectronics. Herein, we disclose that volume-conserving photoisomerization of a unique series of acceptor-donor-acceptor (A-D-A) non-fullerene acceptors (NFAs) acts as a surrogate towards their subsequent photochemical reaction. Among A-D-A NFAs with fused, semi-fused and non-fused backbones, fully non-fused PTIC, representing one of rare existing samples, exhibits not only excellent photochemical tolerance in aerobic condition, but also efficient performance in solar cells.

Simple Non-Fused Electron Acceptors Leading to Efficient Organic Photovoltaics.

Despite the remarkable progress achieved in recent years, organic photovoltaics (OPVs) still need work to approach the delicate balance between efficiency, stability, and cost. Herein, two fully non-fused electron acceptors, PTB4F and PTB4Cl, are developed via a two-step synthesis from single aromatic units. The introduction of a two-dimensional chain and halogenated terminals for these non-fused acceptors plays a synergistic role in optimizing their solid stacking and orientation, thus promoting an elongated exciton lifetime and fast charge-transfer rate in bulk heterojunction blends.

Fabrication of superhydrophobic surfaces by dislocation-selective chemical etching on aluminum, copper, and zinc substrates.

A surface roughening method by simple chemical etching was developed for the fabrication of superhydrophobic surfaces on three polycrystalline metals, namely aluminum, copper, and zinc. The key to the etching technique was the use of a dislocation etchant that preferentially dissolves the dislocation sites in the grains. The etched metallic surfaces, when hydrophobized with fluoroalkylsilane, exhibited superhydrophobic properties with water contact angles of larger than 150 degrees, as well as roll-off angles of less than 10 degrees for 8-microL drops.

Investigation of Calcium Carbonate Scaling Inhibition and Scale Morphology by AFM.

The calcium carbonate scale inhibition by two inhibitors, polyacrylic acid (PAA) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), has been studied in two heat transfer systems: recirculating cooling water and pool boiling systems. It is found that PBTCA has a better inhibition effect than PAA under identical conditions. The inhibition effect increases with increasing fluid velocity for the cooling water system, whereas in the presence of inhibitors, the fluid velocity has less effect on the scaling behavior.