Technical University of Berlin

About: Technical University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Quantum dot & Laser. The organization has 27292 authors who have published 59342 publications receiving 1414623 citations. The organization is also known as: Technische Universität Berlin & TU Berlin.

Nucleophile Carben-Chemie

Abstract: Das Bis-[1.3-diphenyl-imidazolidinyliden-(2)] zeigt grose Neigung zur Dissoziation in zwei Carbene. Reaktionen mit dieser leicht zuganglichen Carben-Quelle fuhrten zum Verstandnis der nucleophilen Carben-Chemie. Es wird untersucht, ob und wo sich besonders stabile Carbene finden, und es ergibt sich, das ein uberraschend groses Feld praparativer Moglichkeiten und theoretischer Erkenntnisse auf die Bearbeitung wartet.

Aluminium Foam Sandwich Panels: Manufacture, Metallurgy and Applications

Abstract: Sandwich panels consisting of a highly porous aluminium foam core and aluminium alloy face sheets are manufactured by roll-bonding aluminium alloy sheets to a densified mixture of metal powders – usually Al-Si or Al-Si-Cu alloys with 6–8% Si and 3–10% Cu – and titanium hydride, and foaming the resulting three-layer structure by a thermal treatment. We review the various processing steps of aluminium foam sandwich (AFS) and the metallurgical processes during foaming, compare the process to alternative ways to manufacture AFS, e.g. by adhesive bonding, and give an overview of the available literature. Two ways to treat AFS after foaming are presented, namely forging and age-hardening. Some current and potential applications are described and the market potential of AFS is assessed.

Molecular Beam Epitaxy

Abstract: MBE is a versatile technique for growing thin epitaxial structures made of semiconductors, metals or insulators [7.1] (see also the definition given in Sect. 6.1.3). What distinguishes MBE from previous vacuum deposition techniques is its significantly more precise control of the beam fluxes and growth conditions. Because of vacuum deposition, MBE is carried out under conditions far from thermodynamic equilibrium and is governed mainly by the kinetics of the surface processes occurring when the impinging beams react with the outermost atomic layers of the substrate crystal. This is in contrast to other epitaxial growth techniques, such as LPE or atmospheric pressure VPE, which proceed at conditions near thermodynamic equilibrium and are most frequently controlled by diffusion processes occurring in the crystallizing phase surrounding the substrate crystal.

InAs-InGaAs quantum dot VCSELs on GaAs substrates emitting at 1.3 [micro sign]m

Abstract: Pulsed lasing at 1.3 /spl mu/m via the exciton ground state is demonstrated for vertical cavity surface emitting lasers containing three uncoupled sheets of InAs quantum dot active layers. The structures are grown directly on GaAs substrates and when fabricated include selectively oxidised AlO current apertures, intracavity metal contacts, and AlO/GaAs distributed Bragg reflectors. Experimental devices operate pulsed at room temperature with threshold currents below 2 mA and differential slope efficiencies above 40%.