High In-containing long wavelength GaInN nanostructures on semi-polar surfaces

• Antragsteller: Dr. Michael Jetter
• Fachliche Zuordnung: Experimentelle Physik der kondensierten Materie
• Förderung: Förderung von 2008 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 48042628

In spite of the tremendous success of nitride semiconductors in optoelectronics for the UV and blue spectral range, they still suffer from strong piezoelectric fields at the heterointerfaces and problems with high indium incorporation in GaInN layers, which limits the extension of these devices to the green or red spectral range up to now. With this project within the research group “Polarization field control in light emitters” we like to target this green, respectively red spectral region, by depositing In-rich GaInN quantum wells on GaN nano-pyramids fabricated by selective epitaxy. The sidewalls of these pyramids consist of semi-polar surfaces so that the electric field at the corresponding GaN/GaInN interfaces will be strongly reduced. In addition, a larger amount of indium can be embedded at these surfaces as compared to polar surfaces. In the first funding period we have focused on the fabrication and the structural characterization of micro-pyramids of different sizes to reveal the different deposition conditions for emission in the green and orange-red spectral range. We have found the predicted higher In-incorporation and regions of different carrier confinement on the pyramid. In the second part of the project we especially concentrate on the development of LED structures with high Indium containing nano-pyramids as active region. Therefore, we have to investigate and control on one hand the In-incorporation to achieve emission in the red spectral range. On the other hand, for device applications, we have to overgrow the samples completely. In combination with the other activities of the research group members we can get deep insight into the emission behavior of nanostructures on semi-polar surfaces and contribute to the development of active regions for the green to red spectral range.

• DFG-Verfahren: Forschungsgruppen
• Teilprojekt zu: FOR 957: Polarization Field Control in Nitride Light Emitters
• Beteiligte Person: Professor Dr. Peter Michler