Dr Martin Frentrup

Being fascinated by crystallography with all its “facets”, I joined the experimental nanophysics and photonics group at Technische Universität Berlin in 2008. Here I worked for my diploma thesis (i.e. to MSc level) on MOVPE growth and basic XRD characterisation of semi-polar GaN.

Afterwards I worked for different national (German) and European research projects on the growth and characterisation of nitride based materials for use in blue-violet laser diodes and as calibration standards for SIMS measurements. The main focus of our research activities lay on the p-doping of GaN with Mg, the InxGa1-xN growth with indium contents (x) up to 30 %, and the optimisation of laser diode design to increase device efficiencies.

With the end of these projects I changed my research activities back again to the structural characterisation of semi-polar and non-polar crystal orientations by X-ray diffraction. In such orientations one often observes anisotropic strain, which is highly influenced by the material composition and the chosen parameters during the crystal growth process. One of the aims was to investigate the origins for the structural anisotropy, and to study the influence of strain on the surface morphology. The activities were highlighted by a one month research visit at the Tata Institute of Fundamental Research (TIFR) in Mumbai at the beginning of 2013. Beside the performance of X-ray experiments, we started with polarisation-resolved transmission experiments here to investigate the anisotropic optical nature of AlxGa1-xN and InxAl1-xN. This ends up in very fruitful collaborations with different research groups in Europe and India on the theoretical and experimental side.

Then have a look on my researcher profile, Google Scholar, or LinkedIn: LinkedIn profile.