No abstract

Facile control over the morphology of phase pure tin monosulfide (SnS) thin films, a promising future absorber for thin film solar cells, is enabled by controlling the growth kinetics in vapor transport deposition of congruently evaporated SnS. The pressure during growth is found to be a key factor in modifying the final shape of the SnS grains. The optimized cube‐like SnS shows p‐type with the apparent carrier concentration of ≈1017 cm−3 with an optical bandgap of 1.32 eV. The dense and flat surface morphology of 1 µm thick SnS combined with the minimization of pinholes directly leads to improved diode quality and increased shunt resistance of the SnS/CdS heterojunction (cell area of 0.30 cm2). An open‐circuit voltage of up to 0.3068 V is achieved, which is independently characterized at the Korea Institute of Energy Research (KIER). Detailed high‐resolution transmission electron microscopy analysis confirms the absence of detrimental secondary phases such as Sn2S3 or SnS2 in the SnS grains or at intergrain boundaries. The initial efficiency level of 98.5% is maintained even after six months of storage in air, and the final efficiency of the champion SnS/CdS cell, certified at the KIER, is 2.938% with an open‐circuit voltage of 0.2912 V.

Manganese dioxide (MnO 2 ) materials have received much attention as promising pseudocapacitive materials owing to their high theoretical capacitance and natural abundance. Unfortunately, the charge storage performance of MnO 2 is usually limited to commercially available mass loading electrodes because of the significantly lower electron and ion migration kinetics in thick electrodes. Here, an alternatively assembled 2D layered material consisting of exfoliated MnO 2 nanosheets and nitrogen-doped carbon layers for ultrahighmass-loading supercapacitors without sacrificing energy storage performance is reported. Layered birnessite-type MnO 2 is efficiently exfoliated and intercalated by a carbon precursor of dopamine using a fluid dynamic-induced process, resulting in MnO 2 /nitrogen-doped carbon (MnO 2 /C) materials after self-polymerization and carbonization. The alternatively stacked and interlayer-expanded structure of MnO 2 /C enables fast and efficient electron and ion transfer in a thick electrode. The resulting MnO 2 /C electrode shows outstanding electrochemical performance at an ultrahigh mass loading of 19.7 mg cm −2 , high gravimetric and areal capacitances of 480.3 F g −1 and 9.4 F cm −2 at 0.5 mA cm −2 , and rapid charge/discharge capability of 70% capacitance retention at 40 mA cm −2 . Furthermore, asymmetric supercapacitor based on high-mass-loading MnO 2 /C can deliver an extremely high energy of 64.2 Wh kg −1 at a power density of 18.8 W kg −1 in an aqueous electrolyte.

Novel photocatalysts (TiO2@TiO1−xNx) with the core–shell structure, prepared by controlled nitridation of TiO2 microspheres, show photocatalytic activity under visible-light irradiation.

In the Figure S22 legend of the article's original Supplemental Information PDF, the word ''after'' was incorrectly used instead of ''before'' in the following sentence: ''Cyclic voltammograms were acquired in a non-faradaic region at different scan rates after the (A) first, (B) 10th, and (C) 100th cycle, respectively.'' The Supplemental Information has now been corrected online, and the authors regret the error.

One-dimensional heterostructures consisting of periodically modulated bismuth telluride tube/wire were synthesized by galvanic displacement reaction of Co/Ni multi-segmented sacrificial nanowires. Utilizing the difference in redox potential and corrosion behavior of Co and Ni, segments, dimension, composition, and structure of the individual segments were also precisely engineered. The programmable ability to synthesize heterostructures with simultaneously modulation of various dimensions in ambient conditions may lead to an effective route to synthesize high performance nanodevices including nanoelectronics, optoelectronics, sensors, and thermoelectrics.

No abstract

Combustion of inorganic powder mixtures is not only one of the chemical routes of fabrication of advanced inorganic materials but is also drawing attention as a high-temperature process to grow inorganic nanocrystals of various shapes and morphology.