Azatriangulene-Based Conductive C═C Linked Covalent Organic Frameworks with Near-Infrared Emission.

Two near-infrared (NIR) emissive π-conjugated covalent organic frameworks (COFs) pTANG1 and pTANG2 are synthesized using Knoevenagel condensation of trioxaazatriangulenetricarbaldehyde (TATANG) with benzene- and biphenyldiacetonitriles, respectively. The morphology of the COFs is affected by the size of TATANG precursor crystals. Donor-acceptor interactions in these COFs result in small bandgaps (≈1.

Design of Furan-Based Acceptors for Organic Photovoltaics.

We explore a series of furan-based non-fullerene acceptors and report their optoelectronic properties, solid-state packing, photodegradation mechanism and application in photovoltaic devices. Incorporating furan building blocks leads to the expected enhanced backbone planarity, reduced band gap and red-shifted absorption of these acceptors. Still, their position in the molecule is critical for stability and device performance.

Improving Environmental and Operational Stability of Polymer Field-Effect Transistors by Doping with Tetranitrofluorenone.

Operational instability of organic field-effect transistors (OFETs) is one of the key limitations for applications of printed electronics. Environmental species, especially oxygen and water, unintentionally introduced in the OFET channel, can act as either dopants or traps for charge carriers, affecting the electrical characteristics and stability of devices. Here, we report that intentional doping of the benchmark p-type semiconducting polymer (DPP-DTT) with 2,4,5,7-tetranitrofluorenone (TeNF) markedly improves the operational and environmental stability of OFETs.

Decoupling Strategy for Enhanced Syngas Generation from Photoelectrochemical CO Reduction.

Photoelectrochemical CO reduction into syngas (a mixture of CO and H) provides a promising route to mitigate greenhouse gas emissions and store intermittent solar energy into value-added chemicals. Design of photoelectrode with high energy conversion efficiency and controllable syngas composition is of central importance but remains challenging. Herein, we report a decoupling strategy using dual cocatalysts to tackle the challenge based on joint computational and experimental investigations.

Nitroaromatics as n-type organic semiconductors for field effect transistors.

The nitro group (NO2) is one of the most common electron-withdrawing groups but it has rarely been used in the design of organic semiconductors (OSCs). Herein, we report the n-type semiconducting behavior of simple fluorenone derivatives functionalized with NO2 and CN groups. While the electron mobilities measured in the thin film field-effect transistors are modest (10-6-10-4 cm2 V-1 s-1), the nitrofluorenone OSCs offer excellent air-stability and remarkable tunability of energy levels via facile modification of the substitution pattern.

Gallium nitride nanowire as a linker of molybdenum sulfides and silicon for photoelectrocatalytic water splitting.

The combination of earth-abundant catalysts and semiconductors, for example, molybdenum sulfides and planar silicon, presents a promising avenue for the large-scale conversion of solar energy to hydrogen. The inferior interface between molybdenum sulfides and planar silicon, however, severely suppresses charge carrier extraction, thus limiting the performance. Here, we demonstrate that defect-free gallium nitride nanowire is ideally used as a linker of planar silicon and molybdenum sulfides to produce a high-quality shell-core heterostructure.

Photoelectrochemical CO Reduction into Syngas with the Metal/Oxide Interface.

Photoelectrochemical (PEC) reduction of CO with HO not only provides an opportunity for reducing net CO emissions but also produces value-added chemical feedstocks and fuels. Syngas, a mixture of CO and H, is a key feedstock for the production of methanol and other commodity hydrocarbons in industry. However, it is challenging to achieve efficient and stable PEC CO reduction into syngas with controlled composition owing to the difficulties associated with the chemical inertness of CO and complex reaction network of CO conversion.