Asymmetric electrode geometry induced photovoltaic behavior for self-powered organic artificial synapses

Optoelectronic synapses have attracted considerable attention because of their promising potential in artificial visual perception systems for neuromorphic computing. Despite remarkable progress in mimicking synaptic functions, reduction of energy consumption of artificial synapses is still a substantial obstacle that is required to be overcome to promote advanced emerging applications. Herein, we propose a zero-power artificial optoelectrical synapses using ultrathin organic crystalline semiconductors, which can be self-driven by exploiting the photovoltaic effect induced by asymmetric electrode geometry contacts. The photogenerated charge carrier collection at the two electrodes is unbalanced due to the asymmetric contacts, leading to the in-plane current without bias voltage. Our devices successfully mimic a range of important synaptic functions, such as paired-pulse facilitation (PPF) and spike rate-dependent plasticity (SRDP). Furthermore, we demonstrate that our devices can realize the simulation of image sharpening under self-driven optical-sensing synaptic operations, offering prospects for the development of retinomorphic visual systems.

Designing C6N6/C2N van der Waals heterostructures for photogenerated charge carrier separation

A new two-dimensional C6N6/C2N van der Waals heterostructure is proposed to realize photocatalytic water splitting. The work function difference promotes charge transfer from the C2N to C6N6 layer.

Recent Advances in the Fabrication of All-Solid-State Nanostructured TiO2-Based Z-scheme Heterojunctions for Environmental Remediation

Nanostructured TiO2-based Z-scheme heterojunctions have been widely accepted to be among the most effective photocatalysts for environmental remediation owing to their broadened light absorbance, high efficiency of photogenerated charge carrier separation, and well-preserved strong oxidation and reduction capability. In this review, we will first introduce the photogenerated charge carrier transportation mechanism of three different types of Z-scheme heterojunction systems, namely, liquid-phase Z-scheme photocatalytic system, all-solid-state indirect Z-scheme photocatalytic system, and all-solid-state direct Z-scheme photocatalytic system. Subsequently, we will describe the recent advances toward the rational design and fabrication of all-solid-state nanostructured TiO2-based Z-scheme heterojunctions. The applications of the thus-constructed all-solid-state nanostructured TiO2-based Z-scheme heterojunctions in the degradation of volatile organic compounds, removal of waste water organic pollutants, and upgradation of greenhouse gas CO2 will then be presented one by one. Finally, the advantages and disadvantages of all-solid-state nanostructured TiO2-based Z-scheme heterojunction for photocatalytic environmental remediation will be briefly discussed, and the direction of future development will be prospected as well.

Protein-Directed Crystalline 2D Fullerene Assemblies

Repeat proteins with engineered tyrosine clamps provide a platform for fullerene assembly into 2D crystalline materials with long range molecular order and photogenerated charge carrier capacity. Thus, the self-assembling hybrid material allows to utilise the innate properties of fullerenes, demonstrating the potential of engineered protein-based functional materials.

Protein-Directed Crystalline 2D Fullerene Assemblies

Repeat proteins with engineered tyrosine clamps provide a platform for fullerene assembly into 2D crystalline materials with long range molecular order and photogenerated charge carrier capacity. Thus, the self-assembling hybrid material allows to utilise the innate properties of fullerenes, demonstrating the potential of engineered protein-based functional materials.