Search

Due to the efficient photocarrier separation and collection coming from their distinctive band structures, superlattice nanowires (NWs) have great potential as active materials for high-performance optoelectronic devices. In this work, InGaZnO NWs with superlattice structure and controllable stoichiometry are obtained by ambient-pressure chemical vapor deposition. Along the NW axial direction, perfect alternately stacking of InGaO(ZnO)

Because of their fascinating properties, two-dimensional (2D) nanomaterials have attracted a lot of attention for developing next-generation electronics and optoelectronics. However, there is still a lack of cost-effective, highly reproducible, and controllable synthesis methods for developing high-quality semiconducting 2D monolayers with a sufficiently large single-domain size. Here, utilizing a NaOH promoter and W foils as the W source, we have successfully achieved the fabrication of ultralarge single-domain monolayer WS2 films via a modified chemical vapor deposition method. With the proper introduction of a NaOH promoter, the single-domain size of monolayer WS2 can be increased to 550 μm, while the WS2 flakes can be well controlled by simply varying the growth duration and oxygen concentration in the carrier gas. Importantly, when they are fabricated into global backgated transistors, WS2 devices exhibit respectable peak electron mobility up to 1.21 cm2 V-1 s-1, which is comparable to those of many state-of-the-art WS2 transistors. Photodetectors based on these single-domain WS2 monolayers give an impressive photodetection performance with a maximum responsivity of 3.2 mA W-1. All these findings do not only provide a cost-effective platform for the synthesis of high-quality large single-domain 2D nanomaterials, but also facilitate their excellent intrinsic material properties for the next-generation electronic and optoelectronic devices.

Spinel oxides (AB2O4) with unique crystal structures have been widely explored as promising alternative catalysts for efficient oxygen evolution reactions; however, developing novel methods to fabr...

As an important semiconductor nanomaterial, InP nanowires (NWs) grown with a typical vapor–liquid–solid mechanism are still restricted from their low electron mobility for practical applications. Here, nonpolar-oriented defect-free wurtzite InP NWs with electron mobility of as high as 2000 cm2 V–1 s–1 can be successfully synthesized via Pd-catalyzed vapor–solid–solid growth. Specifically, PdIn catalyst particles are involved and found to expose their PdIn{210} planes at the InP nucleation frontier due to their minimal lattice mismatch with nonpolar InP{2110} and {1100} planes. This appropriate lattice registration would then minimize the overall free energy and enable the highly crystalline InP NW growth epitaxially along the nonpolar directions. Because of the minimized crystal defects, the record-high electron mobility of InP NWs (i.e., 2000 cm2 V–1 s–1 at an electron concentration of 1017 cm–3) results, being close to the theoretical limit of their bulk counterparts. Furthermore, once the top-gated d...

Because of sluggish kinetics of the oxygen evolution reaction (OER), designing low-cost, highly active, and stable electrocatalysts for OER is important for the development of sustainable electrochemical water splitting. Here, {112} high-index facet exposed porous Co3O4 nanosheets with oxygen vacancies on the surface have been successfully synthesized via a simple hydrothermal method followed by NaBH4 reduction. As compared with the pristine and other faceted porous Co3O4 nanosheets (e.g., {110} and {111}), the as-prepared {112} faceted porous nanosheets exhibit a much lower overpotential of 318 mV at a current density of 10 mA cm–2. Importantly, these nanosheets also give excellent electrochemical stability, displaying an insignificant change in the required overpotential at a current density of 10 mA cm–2 even after a 14 h long-term chronoamperometric test. All these superior OER activity and stability could be attributed to their unique hierarchical structures assembled by ultrathin porous nanosheets, ...