11 research outputs found
Supplemental Material, Support_Figures - A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin
<p>Supplemental Material, Support_Figures for A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin by Torbjørn Rage Paulsen, Sebastian Stiller, Klaus Weber, Claudia Donath, Gudrun Schreiband, and Knut Helge Jensen in Toxicology Research and Application</p
Scanning electron microscopy of cells treated with biocides.
<p>(A) Untreated control in Sodium phosphate buffer; (B) 0.75% EUX (0.675% PE + 0.075% EHG); (C) 1.125% PE; (D) 0.125% EHG.</p
ATP-content of <i>E</i>. <i>coli</i> exposed to EUX, PE and EHG (% of untreated control cells).
<p>(A) and (C): Cells suspended in buffer. (B) and (D): Cells suspended in buffer with glucose. Results for two concentrations of EUX and corresponding concentrations of PE (90% of EUX-conc.) and EHG (10% of EUX-conc.) are shown. (A) and (B) 0.75% EUX, (C) and (D) 1.5% EUX. Mean values of three replicates and standard error of the mean are shown.</p
Transmission electron microscopy of cells treated with biocides.
<p>(A) Untreated control in Sodium phosphate buffer; (B) 0.75% EUX (0.675% PE + 0.075% EHG); (C) 1.125% PE; (D) 0.125% EHG. Inset in (B) shows leakage of cytoplasmic material out of the cell membrane (not to scale).</p
Supplemental Material, Appendix1 - A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin
<p>Supplemental Material, Appendix1 for A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin by Torbjørn Rage Paulsen, Sebastian Stiller, Klaus Weber, Claudia Donath, Gudrun Schreiband, and Knut Helge Jensen in Toxicology Research and Application</p
DNA-content of cells exposed to EUX, PE and EHG (% of total DNA pool measured for lysed cells).
<p>Results for three concentrations of EUX and corresponding concentrations of PE (90% of EUX-conc.) and EHG (10% of EUC-conc.) are shown. (A) 0.75% EUX, (B) 1.25% EUX, (C) 1.5% EUX. Mean values of three replicates and standard error of the mean are shown.</p
Supplemental Material, Support_Tables - A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin
<p>Supplemental Material, Support_Tables for A 90-day toxicity and genotoxicity study with high-purity phenylcapsaicin by Torbjørn Rage Paulsen, Sebastian Stiller, Klaus Weber, Claudia Donath, Gudrun Schreiband, and Knut Helge Jensen in Toxicology Research and Application</p
Transient Photovoltage in Perovskite Solar Cells: Interaction of Trap-Mediated Recombination and Migration of Multiple Ionic Species
It
is highly probable that perovskite solar cells (PSCs) are mixed
electronic-ionic conductors, with ion migration being the driving
force for PSC hysteresis. However, there is much that is not understood
about the interaction of ion migration with other processes in the
cell. The key question is: what factors of a PSC are influenced when
ions are free to move? In this contribution, we employ a numerical
drift-diffusion model of PSCs to show that the migration of both anions
and cations in interaction with trap-mediated recombination in the
bulk and/or at the surfaces of the perovskite absorber can manifest
both current–voltage hysteresis and unusual nonmonotonic PSC
photovoltage transients. We identify that a key mechanism of this
interaction is the influence of the net ionic charge throughout the
perovskite bulkwhich varies as the ions approach new steady-state
conditionson the distribution of electrons and holes and subsequently
the spatial distribution of trap-mediated recombination modeled after
Shockley Read Hall (SRH) statistics. Relative to intrinsic recombination
mechanisms, SRH recombination can be highly sensitive to local asymmetries
of the electron–hole population. We show that this sensitivity
is key to replicating nonmonotonic transients with multiple time constants,
the forms of which may have suggested multiple processes. This work
therefore supports the conceptualization of the hysteretic behavior
of PSCs as dominated by the interplay between ion migration and trap-mediated
recombination throughout the perovskite absorber
Rb as an Alternative Cation for Templating Inorganic Lead-Free Perovskites for Solution Processed Photovoltaics
Even though perovskite solar cells
have reached 22% efficiency
within a very short span, the presence of lead is a major bottleneck
to its commercial application. Tin and germanium based perovskites
failed to be viable replacements due to the instability of their +2
oxidation states. Antimony could be a possible replacement, forming
perovskites with structure A<sub>3</sub>M<sub>2</sub>X<sub>9</sub>. However, solution processing of Cs, organic ammonium based Sb perovskites
result in the formation of the dimer phase with poor charge transport
properties. Here we demonstrate that Rb can template the formation
of the desired layered phase irrespective of processing methodologies,
enabling the demonstration of efficient lead-free perovskite solar
cells
Inverted Hysteresis in CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> Solar Cells: Role of Stoichiometry and Band Alignment
J–V
hysteresis in perovskite solar cells is known to be
strongly dependent on many factors ranging from the cell structure
to the preparation methods. Here we uncover one likely reason for
such sensitivity by linking the stoichiometry in pure CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPbI<sub>3</sub>) perovskite cells
with the character of their hysteresis behavior through the influence
of internal band offsets. We present evidence indicating that in some
cells the ion accumulation occurring at large forward biases causes
a temporary and localized increase in recombination at the MAPbI<sub>3</sub>/TiO<sub>2</sub> interface, leading to inverted hysteresis
at fast scan rates. Numerical semiconductor models including ion accumulation
are used to propose and analyze two possible origins for these localized
recombination losses: one based on band bending and the other on an
accumulation of ionic charge in the perovskite bulk