Machine Learning
In article number 2400152, Bolong Huang and Mingzi Sun demonstrated the first-principles machine learning method to directly predict the reaction trends towardsmulti-carbon products for the first time by electroreduction of CO2, which is realized simply based on the database constructed by previous density functional theory calculations, supplying fast screening strategies for advanced atomic catalysts in the future.
An asymmetric split-gate phototransistor configuration, called the “asymmetry field-effect phototransistor” (AFEPT) is demonstrated. The structure allows for an effective modulation of the electric-field profile throughout the channel, as well as enhanced photocarrier transport, thereby providing a new platform for improving optoelectronic properties and probing photocarrier dynamics in intrinsic 2D material layers.
The probing of fundamental photophysics is a key prerequisite for the construction of diverse optoelectronic devices and circuits. To date, though, photocarrier dynamics in 2D materials remains unclear, plagued primarily by two issues: a large exciton binding energy, and the lack of a suitable system that enables the manipulation of excitons. Here, a WSe2-based phototransistor with an asymmetric split-gate configuration is demonstrated, which is named the “asymmetry field-effect phototransistor” (AFEPT). This structure allows for the effective modulation of the electric-field profile across the channel, thereby providing a standard device platform for exploring the photocarrier dynamics of the intrinsic WSe2 layer. By controlling the electric field, this work the spatial evolution of the photocurrent is observed, notably with a strong signal over the entire WSe2 channel. Using photocurrent and optical spectroscopy measurements, the physical origin of the novel photocurrent behavior is clarified and a room-temperature exciton binding energy of 210 meV is determined with the device. In the phototransistor geometry, lateral p–n junctions serve as a simultaneous pathway for both photogenerated electrons and holes, reducing their recombination rate and thus enhancing photodetection. The study establishes a new device platform for both fundamental studies and technological applications.
Recent experimental developments on fluorographenes (FGs) and fluorographene composites (FG-Cs), including synthesis methods, electro-physical properties, intrinsic activity, and the first principle/density functional theory (DFT) study, are presented. The wide applications, energy systems to biomedical and optoelectronics to the aerospace industry are also summarized. This review aims to provide the synergy between experimental and theoretical study of FG-Cs for next-generation catalyst engineering.
Fluorographenes (FGs) are the youngest family of graphene derivatives 2D layer-structure, which has changed the hybridization state from sp2-to-sp3 carbon and unique CF bonds impacting physical and chemical properties. Due to various types of CF bonds, wide bandgap, tunable F/C ratios, and unique nanostructure, the FGs show attractive physicochemical properties. Owing to the extraordinary properties, the researchers have recently paid attention to exploring FGs into fluorographene composites (FG-Cs) as a potential candidate for fundamental advances in the field of the energy system, optoelectronic, biomedical, and aeronautics. Despite their promise, in-depth experimental and theoretical studies of FGs over FG-Cs are not explored systematically. This review focuses on the recent experimental developments on FGs and FG-Cs, including fundamentals and electrophysical properties, synthesis methods, conductivity, hydrophobicity, and magnetic nature. Further, for the validation, the theoretical studies, first-principle study/density functional theory emphasize their real intrinsic activity, stability, and effects of F content, defects, and doping mechanism. Finally, the wide applications, energy systems to biomedical and optoelectronics to the aerospace industry, along with challenges and future perspectives, are also discussed. This review aims to conclude valuable insights into the fundamental science and perspective toward highly efficient FG-C-based catalysts engineering in advanced applications.
