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Room-temperature lasing based on low-dimensional GaAs nanowires (NWs) is one of the most critical and challenging issues in realizing near-infrared lasers for nanophotonics. In this article, the random lasing characteristics based on GaAs NW arrays have been discussed theoretically. According to the simulation, GaAs/AlGaAs core–shell NWs with an optimal diameter, density, and Al content in the shell have been grown. Systematic morphological and optical characterizations were carried out. It is found that the GaAs NWs with the additional growth of the AlGaAs shell exhibit improved emission by about 2 orders of magnitude at low temperatures, which can be attributed to the suppression of crystal defects. At room temperature, lasing was observed with a threshold around 70.16 mW/cm2, and the random lasing mechanism was discussed in detail. This work is of great significance for the design of random cavities based on semiconductor NWs, which is important for optoelectronic integration.

Inverted perovskite light-emitting diodes (PeLEDs) based on quantum dots (QDs) are some of the most promising candidates for next-generation lighting and display applications. Due to the strong fluorescence quenching caused by zinc oxide, high performance in such inverted devices remains challenging. Here, we report an efficient inverted green CsPbBr3QDs LED using an emitting buffer layer. Ultrathin CsPbBr3QD emitters act as the buffer layer to reduce the interface luminescence quenching reaction at the ZnO/upper emitting layer interface, increasing the probability of exciton recombination within the emissive layer and regulating the charge transport, leading to effective carrier recombination. The resulting device exhibits an external quantum efficiency of 13.1%, enhanced by about 4.7 times compared with that without a buffer layer device. This work provides a path to fabricating high-performance inverted PeLEDs.

CeO2nanocubes (c-CeO2), nanoparticles (p-CeO2), and nanorods calcined at 500 °C (r-CeO2-500) and 700 °C (r-CeO2-700) were used as supports to synthesize a series of Ni/CeO2catalysts for the propane combustion and oxidative dehydrogenation of propane (ODHP) reactions. The Ni-CeO2interaction greatly promotes the reducibility of CeO2, but CeO2morphology-dependent Ni-CeO2interaction was observed to form different speciation of Ni species (Ni2+dissolved in CeO2, highly dispersive NiO, NiO aggregate) and oxygen species (strongly activated oxygen species, medially activated oxygen species, weakly activated oxygen species) in various Ni/CeO2catalysts. Ni-CeO2interaction is stronger in Ni/c-CeO2catalysts than in other Ni/CeO2catalysts. Different morphology-dependences of Ni/CeO2catalysts in propane combustion and ODHP reactions were observed. The Ni/r-CeO2-500 catalyst with the largest strongly activated oxygen species is most catalytic active in the propane combustion reaction while the Ni/c-CeO2catalyst with the largest amount of weakly activated oxygen species exhibits the best catalytic performance in the ODHP reaction. Thus, the CeO2morphology engineering strategy is effective in finely tuning the metal-CeO2interaction and the reactivity of oxygen species to meet the requirements of different types of catalytic oxidation reactions.