Pd/g-C3N4 stands out for the ORR, and multiple-level descriptors involving basic characteristics, electronic structures, charge transfer and energy are established.

With the advantages of maximum metal utilization, single-atom catalysts (SACs) are emerging as promising catalysts in the CO2 reduction reaction (CO2RR) field. Herein, first-principles calculation is performed to investigate the...

The fluorescence-lifetime imaging microscopy (FLIM) technique is utilized to probe the photoluminescence properties of individual MoS2 flakes. This measurement allows identification of the layer number of the flakes: two fluorescence decay lifetimes (τ1 and τ2) exhibit linear relationships with the layer number. Our investigation of the fluorescence lifetime reveals exciton dynamics in monolayer and multilayers MoS2. We find the distinct difference on the decay rates between A exciton (fast) and B exciton (slow). K′/Γ emission has different decay behaviors with respect to the layer number (N) because of its variable energy in monolayer and multilayer samples. The interplay of these transition channels also plays an important impact on the overall decay. Our results demonstrate that FLIM is an effective measurement for studying the luminescence properties of transition metal dichalcogenides.

The band-edge carrier recombination rate determines the internal quantum efficiency of light-emitting diodes (LEDs), which is predominantly determined by the carrier lifetime. Point defects in transition metal dichalcogenides (TMDs) as dominant nonradiative recombinations affect the carrier lifetimes, hindering photon emission. Uncovering the mechanism of different defect types on carrier lifetimes in TMDs is still controversial and challenging. Here, we combine time-resolved photoluminescence measurement with nonadiabatic molecular dynamics calculation to explore the bandedge carrier lifetime in monolayer WS 2 with three typical kinds of defects. We have found that vacancy defects and compensatory doping defects in TMDs lead to decreased bandedge carrier lifetimes by 2 or 1 order of magnitude compared with pristine WS 2 , respectively. We attribute the difference to the phonon modes involved in electron− phonon coupling caused by defect types. Such an insight into the carrier lifetime can help modulate the defects in TMDs, so as to improve the performance of LEDs in the future.

The development of the resistive switching cross-point array as the next-generation platform for high-density storage, in-memory computing and neuromorphic computing heavily relies on the improvement of the two component devices, volatile selector and nonvolatile memory, which have distinct operating current requirements. The perennial current-volatility dilemma that has been widely faced in various device implementations remains a major bottleneck. Here, we show that the device based on electrochemically active, low-thermal conductivity and low-melting temperature semiconducting tellurium filament can solve this dilemma, being able to function as either selector or memory in respective desired current ranges. Furthermore, we demonstrate one-selector-one-resistor behavior in a tandem of two identical Te-based devices, indicating the potential of Te-based device as a universal array building block. These nonconventional phenomena can be understood from a combination of unique electrical-thermal properties in Te. Preliminary device optimization efforts also indicate large and unique design space for Te-based resistive switching devices.