Accelerated interface defect removal in amorphous crystalline silicon heterostructures using pulsed annealing and microwave heating

We present postdeposition annealing experiments on undoped amorphous n type crystalline silicon [ i a Si H n c Si i a Si H ] heterostructures used as precursors for a Si H c Si high efficiency solar cells. Comparing conventional hotplate with pulsed microwave heating we obtain excellent interface passivation and demonstrate that microwave annealing proceeds significantly faster. The effect is ascribed to the details of microwave absorption, which selectively affects Si H bonds and thus facilitates hydrogen bond reconfiguration needed for interface passivation. Infrared absorption spectroscopy shows that the main contribution to passivation is not stemming from bulk hydrogen reconfiguration. This suggests a hydrogen rich interface layer, whose occurrence depends on a Si H deposition conditions, to be responsible for the fast annealin

Laserdiagnostische und plasmatechnologische Grundlagen zur Verminderung von Emissionen und Kraftstoffverbrauch bei DI-Verbrennungsmotoren. Teilvorhaben: Orts- und zeitaufgeloeste Untersuchung des Schadstoffabbaus im Plasma Abschlussbericht

The dissertation describes basic and applied research on gas discharges with dielectric constraints, which are assumed to have great potential in purification of off-gases of industrial combustion systems.Im Rahmen der vorliegenden Dissertation wurden grundlegende als auch angewandte Forschungen im Bereich dielektrisch behinderter Entladungen vorgenommen. Derartige Gasentladungen zeigen ein grosses Potential zur Reinigung von Abgasen aus technischen Verbrennungssystemen. (orig.)Available from TIB Hannover: F01B1472+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Intrinsic modification of repair mortars made with EVA and CaO, impacts at the earlier ages

Many studies have been realised on polymer-modified mortars (PMMs). Among the polymers used, ethylene vinyl acetate (EVA) has revealed evident interaction between calcium ions and its acetate groups. Most of the studies have shown a positive impact of EVA on mortar performance, which is enhanced by the combination of the EVA with calcium oxide CaO. However, there is still a lack of understanding of the nature of these interactions and no clear link has been established between these interactions and the properties of the cementitious materials at early ages. This article aims to tackle this topic by focusing on the evolution of EVA particles in a pore solution and the properties of a cement modified with EVA and CaO, especially the rheological behaviour. As results, it is observed that the zeta potential of the pore solution decreases when EVA is added. Furthermore, the hydrodynamic radius of this polymer tends to increase over time in the pore solution. On the other hand, the EVA tends to delay the setting time while the CaO accelerates it. For the rheological state, EVA tends to govern the plastic viscosity of the cement paste while CaO governs the yield stress and these parameters are not affected by the mixing time during the first 100 min. Their combination enhances these rheological parameters

Interplay of amorphous silicon disorder and hydrogen content with interface defects in amorphous crystalline silicon heterojunctions

We analyze the dependence of the interface defect density Dit in amorphous crystalline silicon a Si H c Si heterojunctions on the microscopic properties of ultrathin 10 nm undoped a Si H passivation layers. It is shown that the hydrogen bonding and network disorder, probed by infrared and photoelectron spectroscopy, govern the initial Dit and its behavior upon a short thermal treatment at 200 C. While the initial Dit is determined by the local and nonequilibrated interface structure, the annealed Dit is defined by the bulk a Si H network strain. Thus it appears that the equilibrated a Si H c Si interface does not possess unique electronic properties but is governed by the a Si H bulk defect

Primary structure of a molluscan egg-specific NADase, a second-messenger enzyme.

An egg-specific NADase has been purified from the ovotestis of the marine mollusk Aplysia californica. The enzyme converts NAD to cyclic ADP-ribose (cADPR), which is a potent mobilizer of Ca2+. It is likely that the NADase serves to raise Ca2+ levels in the ova at appropriate times. A 1.2-kb cDNA clone containing the complete coding sequence of the native NADase protein was isolated from an unamplified ovotestis cDNA library and represents the first cloning of an NADase that generates cADPR. In vitro translation studies indicate that the protein initially has a signal sequence that may help to target it to discrete vesicles of the ova in which it is found. There are 12 cysteines in the open reading frame, two of these being in the signal sequence. No part of the sequence has significant similarity to other proteins or known nucleotide binding site consensus sequences. Northern blot analysis of poly(A)+ selected ovotestis RNA has identified an NADase mRNA of 1.85 kb. In situ hybridization analysis of cryostat sections from ovotestis has shown that the NADase mRNA is restricted to the immature ova, although the NADase protein is present in both immature and mature eggs

Impact of a Si H structural properties on the annealing behavior of a Si H c Si heterostructures used as precursors for high efficiency solar cells

We analyze the dependence of the interface defect density Dit in amorphous crystalline a Si H c Si heterostructures on the microscopic properties of the ultrathin 10nm undoped a Si H films. It is shown that the hydrogen bonding configuration, probed by infrared spectroscopy, determines the a Si H network disorder, which in turn governs the annealing behavior of these structures upon a short thermal treatment at moderate temperatures T 200 C . While the as deposited Dit seems to be determined by the local structure at the interface, the final state of the annealed samples is determined by the bulk a Si H network strain as reflected in the valence band tail slope. Thus it appears valid to treat the equilibrated a Si H c Si interface as a 2D layer that has the projected defect properties of the 3D a Si H bul

Venlo Application Testing (Individual Reports and Additional Data)

This chapter contains supplementary experimental data for the concrete panels of the Venlo Application Tests (AT), as well as individual reports on the analysis of test results. The individual reports were prepared by the respective participants, based on the applied test methods and service life prediction models