Achievement of Polarity Reversion From Al(Ga)-Polar to N-Polar For AlGaN Film on AlN Seeding Layer Grown By a Novel Flow-Modulation Technology

N-polar AlGaN epi-layer was realized on AlN seeding layer grown with a novel flow-modulation method. The polarity reversion from Al(Ga)-polar to N-polar for AlGaN/AlN films was confirmed by KOH etching and subsequent observation with optical microscope as well as high-resolution X-ray diffraction (HR-XRD) measurement. In particular, the dependence of crystalline quality and defect size in the N-polar AlGaN epi-layers on the Ⅴ/Ⅲ ratio was investigated with HR-XRD and scanning electron microscopy (SEM). It was found that as the full width at half maximum (FWHM) value of the X-ray rocking curve (XRC) varied with the Ⅴ/Ⅲ ratio in a "W-shape" for the N–polar AlGaN epi-layers, and a FWHM value as small as 450 arcsec was achieved for the sample grown with a V/III ratio of 988. Moreover, it was revealed by the SEM measurement that the maximum diagonal length of hexagonal cone on the surface of the N-polar AlGaN epi-layers decreased sharply when a Ⅴ/Ⅲ ratio of 1,236 was used although the crystalline quality and the surface morphology of the N-polar AlGaN epi-layers were not improved simultaneously. The peculiar migration of the group-III atoms on the surface of the N-polar AlGaN epi-layer associated with the molar ratio of TMA/(TMA+TMG) was considered to be responsible for this result.

Stabilization of lithium metal anodes by conductive metal–organic framework architectures

The Cu-foil current collectors with Ni3(HITP)2 films were prepared to reduce the energy barrier of the current collector surface and thus provide a uniform seeding layer for the subsequent deposition of Li in Li-ion batteries.

Mixed-trophies two species biofilms driven by Cyanobacteria for biotechnnological applications

<p> </p> <p>Despite photo-biocatalysis developing remarkably and the huge potential of photoautotrophic microorganisms for eco-efficient production scenarios, photo-biotechnology is still in its infancy. The lack of scalable photo-bioreactors that provide efficient light transmission, CO<sub>2</sub> supply, and O<sub>2</sub> degassing and thus enable high cell densities (HCD), constitutes a key bottleneck, especially if cost-sensitive bulk chemicals are the product of choice. Commercialized tubular photo-bioreactors with 100 to 600 mm inner diameter offer a surface area to volume ratio (SA/V) of over 100 m<sup>2</sup> m<sup>-3</sup> enabling the efficient capturing of incident solar radiation.<sup>1</sup> Here we introduce a new generation of photo-bioreactors based on capillary biofilm reactors. The biofilm is composed of two strains, namely the photoautotrophic strain <em>Synechocystis</em> sp. PCC 6803 and the chemoheterotrophic strain <em>Pseudomonas taiwanensis</em> VLB120, which serves as a biofilm supporter strain. <em>Pseudomonas</em> sp. is lowering the pO<sub>2</sub> in the system, which otherwise would toxify the Cyanobacteria. Furthermore, it produces extrapolymeric substances (EPS) and produces a kind of seeding layer promoting the attachment of <em>Synechocystis</em> sp.. <em>Synechocystis</em> sp. on the other hand produces organic compounds and oxygen consumed by <em>Pseudomonas</em> sp. The system is run completely without any organic carbon source.</p> <p>Depending on the functionalities engineered into the biofilm forming organisms, these systems can be used for biotechnological applications. Here, we will present data on the physiology of the mixed trophies biofilm, and the challenging conversion of cyclohexane to caprolactone, and further on to 6-hydroxyadipic acid, both being important monomers for Nylon production.</p> <p> </p> <p><strong>References </strong></p> <ul> <li>[1] Posten, C. Eng. In Life Science. (2009) 9:165-177</li> <li>[2] Hoschek, A. et al Bioresource Technology. (2019) 282: 171-178</li> </ul> <p> </p> <p>tract HTML here.</p>

Transfer printing of polymer light-emitting devices with a small molecular seeding layer featuring thermally activated delayed fluorescence for triplet harvesting

Transfer-printing technology combined with a TADF-based HTL realized a 2-fold enhancement of EL efficiency for a polymer fluorescence emitter.

Selective and efficient solid-phase microextraction of polycyclic aromatic hydrocarbons in water by robust two-dimensional zinc oxide nanosheets grown on a superelastic nickel–titanium alloy fiber prior to determination by HPLC-UV

Oriented 2D ZnO nanosheets were directly grown on a pretreated NiTi fiber without a seeding layer by precisely controllable electrodeposition.