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Currently, one-dimensional all-inorganic CsPbX (X = Br, Cl, and I) perovskites have attracted great attention, owning to their promising and exciting applications in optoelectronic devices. Herein, we reported the exploration of superior photodetectors (PDs) based on a single CsPbI nanorod. The as-constructed PDs had a totally excellent performance with a responsivity of 2.92 × 10 A·W and an ultrafast response time of 0.05 ms, respectively, which were both comparable to the best ones ever reported for all-inorganic perovskite PDs. Furthermore, the detectivity of the PDs approached up to 5.17 × 10 Jones, which was more than 5 times the best one ever reported. More importantly, the as-constructed PDs showed a high stability when maintained under ambient conditions.

Currently, it is still a significant challenge to simultaneously boost various reactions by one electrocatalyst with high activity, excellent durability, as well as low cost. Herein, hybrid trifunctional electrocatalysts are explored via a facile one‐pot strategy toward an efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The catalysts are rationally designed to be composed by FeCo nanoparticles encapsuled in graphitic carbon films, Co2P nanoparticles, and N,P‐codoped carbon nanofiber networks. The FeCo nanoparticles and the synergistic effect from Co2P and FeCo nanoparticles make the dominant contributions to the ORR, OER, and HER activities, respectively. Their bifunctional activity parameter (∆E) for ORR and OER is low to 0.77 V, which is much smaller than those of most nonprecious metal catalysts ever reported, and comparable with state‐of‐the‐art Pt/C and RuO2 (0.78 V). Accordingly, the as‐assembled Zn–air battery exhibits a high power density of 154 mW cm−2 with a low charge–discharge voltage gap of 0.83 V (at 10 mA cm−2) and excellent stability. The as‐constructed overall water‐splitting cell achieves a current density of 10 mA cm−2 (at 1.68 V), which is comparable to the best reported trifunctional catalysts.

The thermal stability of luminescence is important for the application of quantum dots (QDs) in light-emitting devices. The temperature-dependent photoluminescence (PL) intensities and decay times of Mn-doped ZnS, ZnSe, and ZnSeS alloyed core-shell QD films were studied in the temperature range from 80 to 500 K by steady-state and time-resolved PL spectroscopy. It was found that the thermal stability of Mn-doped QD emissions was significantly dependent on the shell thickness and the host bandgap, which was higher than that of workhorse CdSe QDs. Nearly no PL quenching took place in Mn:ZnS QDs with a thick ZnS shell, which kept a high PL quantum yield (QY) of ~50% even at 500 K; and the thermally stable PL was also observed in highly luminescent Mn:ZnSe and Mn:ZnSeS QDs with a quenching temperature over 200 °C. Further, the stability of Mn-doped QDs with different shell thickness at high temperature was also examined through heating-cooling cycling experiments. The PL quenching in the thick shell-coated Mn-doped QDs was almost totally recovered. The PL quenching mechanisms of the Mn(2+) ion emissions were discussed.

CuInS2 (CIS) quantum dots (QDs) have tunable photoluminescence (PL) behaviors in the visible and near infrared spectral range with markedly lower toxicity than the cadmium-based counterparts, making them very promising applications in light emitting and solar harvesting. However, there still remain material- and fabrication- related obstacles in realizing the high-performance CIS-based QDs with well-resolved Mn2+ d-d emission, long emission lifetimes as well as high efficiencies. Here, we demonstrate the growth of high-quality Mn2+-doped CuInS-ZnS (CIS-ZnS) QDs based on a multi-step hot-injection strategy. The resultant QDs exhibit a well-resolved Mn2+ d-d emission with a high PL quantum yield (QY) up to 66% and an extremely long excited state lifetime up to ~3.78 ms, which is nearly two times longer than the longest one of “green” QDs ever reported. It is promising that the synthesized Mn2+-doped CIS-ZnS QDs might open new doors for their practical applications in bioimaging and opto/electronic devices.

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We have reported the enhanced field emission properties of quasialigned 3C-SiC nanowires synthesized via catalyst assisted pyrolysis of polysilazane. The as-synthesized Al-doped SiC nanowires possess a tapered and bamboo-like structure with clear and tiny tips sized in several to tens of nanometers. The fabricated SiC nanowires have extremely low turn-on fields of 0.55−1.54 V μm−1 with an average of ∼1 V μm−1, which is the lowest one ever reported for any type of SiC emitters. The field-enhancement factor has been calculated to be 2983. The superior FE properties can be clearly attributed to the significant enhancements of the tapered and bamboo-like unique morphology and Al doping of SiC nanowires. Density functional theory calculations suggest that Al dopants in 3C-SiC nanowires could favor a more localized state near the Fermi energy, which improves the electron field emissions. We strongly believe that the present work will open a new insight in the fabrication of field emission sources with ultralow turn-on fields enhanced by both shape and doping.

Articles you may be interested inSize dependent optical properties of Si quantum dots in Si-rich nitride/Si3N4 superlattice synthesized by magnetron sputtering Influence of average size and interface passivation on the spectral emission of Si nanocrystals embedded in SiO 2The optical properties of single-crystalline ␣-Si 3 N 4 nanobelts synthesized via catalyst-assisted pyrolysis of polymeric precursor were characterized by absorption, photoluminescence ͑PL͒ and photoluminescence excitation ͑PLE͒. The optical absorption spectrum showed that the nanobelts exhibited indirect absorption behavior with optical band gap of ϳ5.0 eV. Three broad peaks centered at 1.8, 2.3, and 3.0 eV were observed from the room-temperature PL spectrum of the nanobelts. The PLE spectra suggested the existence of multifold energy levels within the gap. A qualitative model was proposed to explain the observed absorption, PL and PLE spectra.