EPHQUAM
research group FOR 957
Polarization field control in nitride light emitters - PolarCoN
Project partners
| Project P1: Prof. Dr. Ferdinand Scholz (Speaker) Institut für Optoelektronik, Universität Ulm Growth of non- and semi-polar GaN quasi substrates by hydride vapor phase epitaxy |
| Project P2: Prof. Dr. Andreas Hangleiter Institut für Angewandte Physik, Technische Universität Braunschweig Physics and Technology of nitride-based non-polar green laser diode structures |
| Project P3: Dr. Michael Jetter and Prof. Dr. Peter Michler Institut für Halbleiteroptik und Funktionelle Grenzflächen, Universität Stuttgart High In-containing GaInN active region: Growth on semi-polar microstructures and time-resolved optical characterization |
| Project P4: PD Dr. Armin Dadgar and Prof. Dr. Alois Krost FNW/IEP/AHE, Otto-von-Guericke Universität Magdeburg Polarization reduced AllnGaN / AllnN MQWs and polarization reduced layers on planar silicon |
| Project P5: Prof. Dr. Michael Kneissl and Dr. Tim Wernicke Institut für Festkörperphysik, Technische Universität Berlin Polarization field control in GaInN quantum well heterostructures on semipolar growth surfaces |
| Project P6: Prof. Dr. Josef Zweck Fakultät für Physik, Universität Regensburg Transmission electron microscopy studies of semi- and non-polar nitrides: surfaces, interfaces and defects |
| Project P7: Dr. Frank Bertram and Prof. Dr. Jürgen Christen FNW/IEP/AFP, Otto-von-Guericke Universität Magdeburg Microscopic Correlation of electronic and Optical Properties with the Crystalline Real Structure of Polarization Field Controlled Group-III-Nitrides |
| Project P8: Prof. Dr. Bernd Witzigmann Universität Kassel Non-Equilibrium Modeling of Carrier Dynamics in IIINitride Optoelectronic Devices |
| Project P9: Prof. Dr. Ferdinand Scholz (Speaker) and Prof. Dr. Klaus Thonke Institut für Optoelektronik (FS), Institut für Quantenmaterie (KT), Universität Ulm 3D GaN based GaInN/GaN structures with reduced piezoelectric polarization |
| Project P10: : Prof. Dr. Ulrich Schwarz (Deputy Speaker) Fakultät für Physik, Universität Freiburg Microscopic analysis of semi- and non-polar nitrides |
Goals
The group aims to control polarization effects in group III nitride-based heterostructures and investigate various approaches towards application in optoelectronic devices. The challenge is to close the so-called “green gap” describing lower efficiency in GaN based green light emitters as opposed to their blue and ultraviolet counterparts and, ultimately, to develop green nitride-based laser diodes. One of the obstacles is thought to be the polar character of GaN and related compounds, in particular for devices grown along the crystalline c-axis. The PolarCoN team will investigate possibilities to close the “green gap” by studying non-polar nitride-based heterostructures and devices. The main approach will be the epitaxial growth of such structures in non- or semipolar directions, which requires new strategies to overcome a number of material and structural problems. Another approach is the minimization of any polarisation induced fields on c-plane surfaces by polarisation matching material combinations like AlInN-GaInN. The group will work on epitaxial growth of defect-free non-polar materials including the development of free-standing non- and semipolar GaN substrates. On such templates, optoelectronic device structures will be grown with a major focus on longer wavelength, non-polar laser diodes. The respective building blocks – active quantum wells, n- and p-type doping, device processing, mirror fabrication etc. – will be developed by the different groups of the consortium and strongly supported by theoretical modelling efforts. This Transregional Research Unit is funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG).
More information available on the PolarCoN website: http://www.gan-polarcon.de/