Defect and interlayer engineering in transition metal dichalcogenides for enhancing potassium storage. - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), MM 65.3
Modulating selectivity of nitrites reduction by leveraging polymer-induced solvation effects. - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), CPP 107.5
Theoretical description of single-Co Kondo effect in atomic Cu wires on Cu(111). - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), O 118.8
Bulk ion conductivity and near surface composition of Ionic Liquid and Zwiterion Ionic Liquid based electrolyte for lithium battery applications. - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), O 121.9
Bulk ion conductivity and near surface composition of Ionic Liquid and Zwitterion Ionic Liquid based electrolyte for sodium battery applications. - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), O 121.10
Surface modification and charge carrier dynamics of materials and structures for semiconductor-based solar water splitting applications under operation conditions. - In: DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM) together with the DPG Division Environmental Physics and the Working Groups Accelerator Physics; Equal Opportunities; Energy; Industry and Business; Physics, Modern IT and Artificial Intelligence, Young DPG, (2020), HL 75.25
New nanostructured apatite-type (Na+,Zn2+,CO32-)-doped calcium phosphates : Preparation, mechanical properties and antibacterial activity. - In: Journal of molecular structure, ISSN 0022-2860, Bd. 1222 (2020), 128932
Im Titel sind "+", "2+" und "2-" hochgestellt, "3" tiefgestellt
Nanoparticles with the sizes in the range (20-30) nm of apatite-type Na+,Zn2+,CO32--doped calcium phosphates were prepared from aqueous solution of Na+-Ca2+-Zn2+-NO3--CO32--PO43- system at molar ratios Ca2+/PO43- =1.67, CО32-/РО43- = 1, Zn2+:Ca2+ = 1:100 or 2:100. The elemental analysis showed growth of Zn2+ content in composition of samples from 0.61 to 1.95 wt% at increasing of Zn2+ amount in an initial solution. According to FTIR and Raman data, B-type substitution of PO43- by CO32- realized in apatite-type calcium phosphates. The mechanical properties study for prepared phases showed the dependence of Young's modulus and compressive strength on Zn2+ amount in their composition. Growth of S. epidermidis after the contact with synthesized apatite containing Na+ (0.25 wt%), Zn2+ (0.61 wt%) and CO32- (1.18 wt%) was significantly delayed with an extension of lag time from 1 to 13-14 h. The prepared sample can be considered as a new prospective biomaterial with antibacterial potential.
https://doi.org/10.1016/j.molstruc.2020.128932
Polyimide@Ketjenblack composite: a porous organic cathode for fast rechargeable potassium-ion batteries. - In: Small, ISSN 1613-6829, Bd. 16 (2020), 38, 2002953, insges. 8 S.
Potassium-ion batteries (PIBs) configurated by organic electrodes have been identified as a promising alternative to lithium-ion batteries. Here, a porous organic PolyimideKetjenblack is demonstrated in PIBs as a cathode, which exhibits excellent performance with a large reversible capacity (143 mAh g^-1 at 100 mA g^-1), high rate capability (125 and 105 mAh g^-1 at 1000 and 5000 mA g^-1), and long cycling stability (76% capacity retention at 2000 mA g^-1 over 1000 cycles). The domination of fast capacitive-like reaction kinetics is verified, which benefits from the porous structure synthesized using in situ polymerization. Moreover, a renewable and low-cost full cell is demonstrated with superior rate behavior (106 mAh g^-1 at 3200 mA g^-1). This work proposes a strategy to design polymer electrodes for high-performance organic PIBs.
https://doi.org/10.1002/smll.202002953
Quantification of the As/P content in GaAsP during MOVPE growth. - In: Applied physics letters, ISSN 1077-3118, Bd. 117 (2020), 6, S. 061601-1-061601-5
Epitaxial integration of direct-bandgap III-V compound semiconductors with silicon requires overcoming a significant lattice mismatch. To this end, GaAsP step-graded buffer layers are commonly applied. The thickness and composition of the individual layers are decisive for the envisaged strain relaxation. We study GaAsP growth by metalorganic vapor phase epitaxy in situ with reflection anisotropy spectroscopy. We find that the growth surface exhibits optical fingerprints of atomically well-ordered surfaces. These allow for tuning the interface preparation between adjacent layers. The spectral position of the characteristic peaks in the RA spectra, which are related to surface-modified bulk transitions, behaves similarly upon an increased As content as does the E1 interband transition of GaAsP at the growth temperature. The impact of strain on this shift is negligible. We thus monitor a bulk property via the surface reconstruction. An empiric model enables quantification of the As content of individual layers directly in situ without growth interruptions and for various surface reconstructions. Our findings are suitable for a simplified optimization of the GaAsP buffer growth for high-efficiency devices.
https://doi.org/10.1063/5.0012948
Augmentation of absorption channels induced by wave-chaos effects in free-standing nanowire arrays. - In: Optics express, ISSN 1094-4087, Bd. 28 (2020), 16, S. 23569-23583
Plenty of issues on quantal features in chaotic systems have been raised since chaos was accepted as one of the intrinsic properties of nature. Through intensive studies, it was revealed that resonance spectra in chaotic systems exhibit complicated structures, which is deeply concerned with sophisticated resonance dynamics. Motivated by these phenomena, we investigate light absorption characteristics of chaotic nanowires in an array. According to our results, a chaotic cross-section of a nanowire induces a remarkable augmentation of absorption channels, that is, an increasing number of absorption modes leads to substantial light absorption enhancement, as the deformation of cross-section increases. We experimentally demonstrate the light absorption enhancement with free-standing Si-nanowire polydimethylsiloxane (PDMS) composites. Our results are applicable not only to transparent solar cells but also to complementary metal-oxide-semiconductor (CMOS) image sensors to maximize absorption efficiency.
https://doi.org/10.1364/OE.398687