@article{nokey,

title = {Selective growth and characterization of GaN nanowires on SiC substrates},

author = {T H\"{o}ldrich and A Wieland and F Pantle and J Winnerl and M Stutzmann},

url = {https://www.sciencedirect.com/science/article/pii/S0022024825001423},

doi = {https://doi.org/10.1016/j.jcrysgro.2025.128194},

issn = {0022-0248},

year  = {2025},

date = {2025-09-01},

journal = {Journal of Crystal Growth},

volume = {665},

pages = {128194},

abstract = {GaN on SiC is a promising material combination for high power devices, where especially nanostructures, such as nanowires or nanofins, are a space and resource saving solution. In this work we demonstrate the selective area growth of GaN nanowires on SiC substrates, using the polytype 6H-SiC. We investigate the influence of the Si- and C-polarity of the substrate on the structural properties of the GaN nanowires by scanning electron microscopy and photoluminescence spectroscopy. On both substrates uniform and hexagonal nanowires are achieved for the respective optimal growth temperature, which is determined to be 20$circ $C higher for Si-polarity. As the polarity combination of the SiC substrate and GaN nanowires strongly influences the electrical properties at the heterointerface due to different charge accumulations, it is necessary to investigate the epitaxial relationship. X-ray diffraction revealed that the GaN nanowires exclusively adopt the orientation of the underlying SiC lattice, leading to an in-plane epitaxial relationship of (11¯00)GaN/(11¯00)6H-SiC. Polarity-selective wet chemical etching and Kelvin probe force microscopy showed that the GaN nanowires preserve the polarity of the substrate, thus, either a predominantly metal-polar (Si-polar/Ga-polar) or non-metal-polar (C-polar/N-polar) orientation is present. The complete epitaxial relationship on both substrate polarities can be identified as (11¯00)[0001]GaN||(11¯00)[0001]6H-SiC for the large majority of NWs at their respective optimum growth temperatures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Temperature-dependent thermal behavior of BTP-4F-12-based organic solar cells},

author = {Z Li and J Zhang and S A Wegener and Y Yan and X Jiang and K Sun and G Pan and T Zheng and M Schwartzkopf and S K Vayalil and C-Q Ma and P M\"{u}ller-Buschbaum},

url = {https://www.sciencedirect.com/science/article/pii/S2211285525004021},

doi = {https://doi.org/10.1016/j.nanoen.2025.111043},

issn = {2211-2855},

year  = {2025},

date = {2025-07-01},

journal = {Nano Energy},

volume = {140},

pages = {111043},

abstract = {Heat is one key factor contributing to performance decreases, which would lead to inevitable morphological changes in the active layers. Common research with ex-situ characterizations ignored the degradation process kinetics, which hinders a comprehensive insight into the underlying thermal degradation mechanisms in organic solar cells (OSCs). In this study, the device thermal stability of BTP-4F-12-based solar cells is investigated with operando tracking of grazing-incidence wide/small-angle X-ray scattering (GIWAXS/GISAXS), providing a deep understanding of temperature-dependent degradation processes. The OSCs show a harsh open-circuit voltage (VOC) loss with increasing temperature, which recovers mostly after getting cooled to low temperature. This behavior is attributed to the charge carrier recombination, π-π stacking distances, and aggregated domains at various temperatures. The irreversible loss of FF and short-circuit current density (JSC) during aging is due to changes in crystallinity and dense π-π stacking. Furthermore, no obvious correlation is found for the sharp decreased FF for the final aged solar cells, suggesting that such a degradation originates not from high temperature but more likely from the heating/cooling process. PBDBTCl-DTBT:BTP-4F-12 solar cells suffer from a more severe thermal degradation compared with PBDB-TF-T1:BTP-4F-12, where the bad miscibility of donor and acceptor is not beneficial to an optimized stable active layer and the intrinsic thermal properties of the polymer donor also affect significantly the stability of the blend films and solar cells. This study reveals a temperature-dependent thermal degradation of OSCs, which broadens our knowledge from common ex-situ characterizations and deepens our understanding of thermal degradation mechanism.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {A low-cost and high-energy aqueous potassium-ion battery},

author = {R L Streng and T Steeger and A Senyshyn and S Abel and P Schneider and C Benning and B M Naranjo and D Gryc and M Z Hussain and O Lieleg and M Elsner and A S Bandarenka and K Cicvari\'{c}},

url = {https://www.sciencedirect.com/science/article/pii/S2095495625001871},

doi = {https://doi.org/10.1016/j.jechem.2025.02.039},

issn = {2095-4956},

year  = {2025},

date = {2025-07-01},

journal = {Journal of Energy Chemistry},

volume = {106},

pages = {523-531},

abstract = {To address challenges related to the intermittency of renewable energy sources, aqueous potassium-ion batteries (AKIBs) are a promising and sustainable alternative to conventional systems for large-scale energy storage. To enable their practical application, maximizing energy density and longevity while minimizing production and material costs is a key goal. In this work, we propose an AKIB consisting only of abundant and cost-efficient materials, which delivers a high energy density of more than 70 Wh kg−1. We combine simple strategies to stabilize the Mn-rich Prussian blue analog cathode by Fe-doping, improving the crystallinity, and tuning the electrolyte composition without employing expensive water-in-salt electrolytes. Using a mixed 2.5 M Ca(NO3)2 + 1.5 M KNO3 electrolyte, we assemble a novel AKIB with a Fe-doped manganese hexacyanoferrate cathode and an organic poly(naphthalene-4-formyl-ethylenediamine) anode. Besides a high energy density, the full cell delivers a specific capacity of approximately 60 mA h g−1, a power density of 5000 W kg−1, and 80% capacity retention after 600 cycles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}