2004, Hebermehl, G., Schefter, J., Schlundt, R., Tischler, Th., Zscheile, H., Heinrich, W.

Field-oriented methods which describe the physical properties of microwave circuits and optical structures are an indispensable tool to avoid costly and time-consuming redesign cycles. Commonly the electromagnetic characteristics of the structures are described by the scattering matrix which is extracted from the orthogonal decomposition of the electric field. The electric field is the solution of an eigenvalue and a boundary value problem for Maxwell’s equations in the frequency domain. We discretize the equations with staggered orthogonal grids using the Finite Integration Technique (FIT). Maxwellian grid equations are formulated for staggered nonequidistant rectangular grids and for tetrahedral nets with corresponding dual Voronoi cells. The interesting modes of smallest attenuation are found solving a sequence of eigenvalue problems of modified matrices. To reduce the execution time for high-dimensional problems a coarse and a fine grid is used. The calculations are carried out, using two levels of parallelization. The discretized boundary value problem, a large-scale system of linear algebraic equations with different right-hand sides, is solved by a block Krylov subspace method with various preconditioning techniques. Special attention is paid to the Perfectly Matched Layer boundary condition (PML) which causes non physical modes and a significantly increased number of iterations in the iterative methods.

2014, Hilt, Oliver

Es wurden GaN-basierte laterale Dioden mit geringer Einsatzspannung und intrinsisch selbstsperrende Transistoren für den Einsatz in Schaltkonvertern realisiert. Transisorergebnisse: - Basierend auf dem p-GaN-Gate Modul wurden selbstsperrende 100 m / 600 V Transistoren mit 1 V Einsatzspannung realisiert. - Durch den Einsatz eines eisendotierten GaN-Puffers konnte die Erhöhung des dynamischen Einschaltwiderstands für das 250 V Schalten auf den Faktor 2.6 reduziert werden. - Die Schaltverluste sind kleiner als für Si-basierte Superjunction MOSFETs. Diodenergebnisse: - Durch die Entwicklung des zurückgesetzten Anodenkontaktes konnten 300 m / 600 V Dioden mit 0.5 V Einsatzspannung realisiert werden. - Die Schaltverluste sind so klein wie bei SiC-basierten HV-Schottkydioden. - Die Dioden wurden erfolgreich im Boost-Konverter (Systemdemonstrator) der Uni Erlangen eingesetzt.

2011, Weyers, M., Knauer, A., Einfeldt, Sven, Rodriguez, Hernan, Kneissl, M., Knüller, V., Tessaro, T., Petzke, T

[no abstract available]

2010, Niehardt, Frank, Grzeganek, Merit, Häckel, Marko, Haselton, Kirk, Kerl, Ralf, Sauer, Franziska

[no abstract available]

2017, Kolbe, Tim, Knauer, Arne, Rass, Jens, Cho, Hyun Kyong, Hagedorn, Sylvia, Einfeldt, Sven, Kneissl, Michael, Weyers, Markus

The effects of composition and p-doping profile of the AlGaN:Mg electron blocking layer (EBL) in 310 nm ultraviolet B (UV-B) light emitting diodes (LEDs) have been investigated. The carrier injection and internal quantum efficiency of the LEDs were simulated and compared to electroluminescence measurements. The light output power depends strongly on the temporal biscyclopentadienylmagnesium (Cp 2 Mg) carrier gas flow profile during growth as well as on the aluminum profile of the AlGaN:Mg EBL. The highest emission power has been found for an EBL with the highest Cp 2 Mg carrier gas flow and a gradually decreasing aluminum content in direction to the p-side of the LED. This effect is attributed to an improved carrier injection and confinement that prevents electron leakage into the p-doped region of the LED with a simultaneously enhanced carrier injection into the active region.

2000, Erbert, G., Brugge, F., Fechner, I., Fredrich, D., Gielow, M., Hofmann, L., Klehr, A., Klein, A., Krause, A., Knauer, A., Olschewsky, R., Oster, A., Rechenberg, I., Ressel, P., Sebastian, J., Selent, R., Smirnitzki, V., Tessaro, T., Thiemann, M., Thies, A., Vogel, K., Wenzel, H., Weyers, M., Würfel, J., Wochatz, P.

[no abstract available]

2005, Heinrich, W., Brunner, F., Kurpas, P., Meliani, C., Rudolph, M., Sidorov, V., Würfl, J.

[no abstract available]

2012, Tränkle, G., Erbert, G., Wicht, A., Luvsandamdin, E.

[no abstract available]

2012, Tränkle, G., Erbert, G., Wicht, A., Spiessberger, S.

[no abstract available]

2007, Würfl, J., Behtash, R., Gesche, R., Janke, B., Klockenhoff, H., Krüger, O., Lossy, R., Chaturvedi, N., Heinrich, W., Knigge, St., Liero, A., Mai, M.

[no abstract available]