Utilization of an Electron-Beam Tester for Determining Internal Electric Field Profiles in Micro-Structured Thin-Film Semiconductor Devices

An electron-beam tester was used to determine the depth profile of the internal potential distribution in an a-Si:H solar cell and hence the internal electric field profile. The a-Si:H solar cells were prepared for the measurements with the electron-beam tester by low-energy chemical plasma beam etching through a plasma-resistant mask structured by electron-beam lithography. In contrast to an earlier work, the solar cells were in situ illuminated and the electric field profiles were determined for new, degraded and in situ annealed solar cells at various cell temperatures. The measuring results demonstrate that the electron-beam testing technique in combination with a suitable micro-structure preparation method is appropriate to measure internal electric field profiles in semiconductor devices as, e.g., solar cells for arbitrarily chosen bias and illumination states

Rotational Effects In The VUV Continuum Of H2

The effects of rotation-vibration interaction and of rotational coupling between the B 2p 1Σu+ and C 2p 1Πu electronic states on the B-X continuum of H2 were investigated spectroscopically using monochromatized synchrotron radiation for selective excitation of rovibronic states. The perturbed continuum intensities observed for the first time agree well with close-coupling calculations also performed. © 1990 IOP Publishing Ltd

The synaptic scaffold protein MPP2 interacts with GABA(A) receptors at the periphery of the postsynaptic density of glutamatergic synapses

Recent advances in imaging technology have highlighted that scaffold proteins and receptors are arranged in subsynaptic nanodomains. The synaptic membrane-associated guanylate kinase (MAGUK) scaffold protein membrane protein palmitoylated 2 (MPP2) is a component of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-associated protein complexes and also binds to the synaptic cell adhesion molecule SynCAM 1. Using superresolution imaging, we show that-like SynCAM 1-MPP2 is situated at the periphery of the postsynaptic density (PSD). In order to explore MPP2-associated protein complexes, we used a quantitative comparative proteomics approach and identified multiple γ-aminobutyric acid (GABA)(A) receptor subunits among novel synaptic MPP2 interactors. In line with a scaffold function for MPP2 in the assembly and/or modulation of intact GABA(A) receptors, manipulating MPP2 expression had effects on inhibitory synaptic transmission. We further show that GABA(A) receptors are found together with MPP2 in a subset of dendritic spines and thus highlight MPP2 as a scaffold that serves as an adaptor molecule, linking peripheral synaptic elements critical for inhibitory regulation to central structures at the PSD of glutamatergic synapses

VUV spectroscopic study of the D1Piu state of molecular deuterium

The D^1\Pi_u - X^1\Sigma_g^+ absorption system of molecular deuterium has been re-investigated using the VUV Fourier -Transform (FT) spectrometer at the DESIRS beamline of the synchrotron SOLEIL and photon-induced fluorescence spectrometry (PIFS) using the 10 m normal incidence monochromator at the synchrotron BESSY II. Using the FT spectrometer absorption spectra in the range 72 - 82 nm were recorded in quasi static gas at 100 K and in a free flowing jet at a spectroscopic resolution of 0.50 and 0.20 cm^{-1} respectively . The narrow Q-branch transitions, probing states of \Pi^- symmetry, were observed up to vibrational level v = 22. The states of \Pi^+ symmetry, known to be broadened due to predissociation and giving rise to asymmetric Beutler-Fano resonances, were studied up to v = 18. The 10 m normal incidence beamline setup at BESSY II was used to simultaneously record absorption, dissociation, ionization and fluorescence decay channels from which information on the line intensities, predissociated widths, and Fano q-parameters were extracted. R-branch transitions were observed up to v = 23 for J = 1-3 as well as several transitions for J = 4 and 5 up to v = 22 and 18 respectively. The Q-branch transitions are found to weakly predissociate and were observed from v = 8 to the final vibrational level of the state v = 23. The spectroscopic study is supported by two theoretical frameworks. Results on the \Pi^- symmetry states are compared to ab initio multi-channel-quantum defect theory (MQDT) calculations, demonstrating that these calculations are accurate to within 0.5 cm^-1.Comment: 16 pages, 10 figures, 2 tables, supplemental material with an additional tabl

Localized topological changes of the plasma membrane upon exocytosis visualized by polarized TIRFM

Imaging of individual secretory granules reveals how exocytosis curves the membrane

Trends in autoionization of Rydberg states converging to the 4s threshold in the Kr-Rb⁺-Sr²⁺ isoelectonic sequence: theory and experiment

We have measured the photoabsorption spectra of the Kr-like ions Rb+ and Sr2+ at photon energies corresponding to the excitation of 4s-np resonances using, the dual laser plasma photoabsorption technique. Dramatic changes in the line profiles, with increasing ionization and also proceeding along the Rydberg series of each ion, are observed and explained by the trends in 4s-transition amplitudes computed within a framework of configuration-interaction Pauli-Fock calculations. Total photoionization cross sections show very good agreement with relative absorption data extracted from the measured spectra