Berlin 2015 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 34: Nitrides: Dots, rods, and structures

HL 34.3: Vortrag

Dienstag, 17. März 2015, 11:45–12:00, EW 201

Nano-scale-characterization of ordered core-shell GaN micropillars — •Marcus Müller^1,2, Gordon Schmidt¹, Eduardo Mayolo¹, Peter Veit¹, Frank Bertram¹, Sergiy Krylyuk^2,3, Ratan Debnath^2,4, Matthew King⁵, Jong-Yoon Ha^2,3, Baomei Wen^2,4, Abhishek Motayed^2,3,4, Albert Davydov², and Jürgen Christen¹ — ¹Institute of Experimental Physics, Otto-von-Guericke-University Magdeburg, Germany — ²Materials Science and Engineering Division, National Institute of Standards and Technology, USA — ³Institute for Research in Electronics and Applied Physics, University of Maryland, USA — ⁴N5 Sensors Inc., USA — ⁵Northrop Grumman ES, USA

In this study we report on the approach of combining top-down principle and the bottom-up processes to fabricate ordered core-shell GaN micropillars. The overgrowth of inductively coupled plasma etched GaN pillars by hydride vapor phase epitaxy produces hexagonally shaped micropillars with vertical non-polar sidewalls and top facet truncated by highly vicinal facets. Scanning electron microscopy measurements of the samples reveal a homogeneous growth. The strain tensors at selected regions of micropillars were analysed, using electron-backscattered-diffraction. Direct correlation of the optical and structural properties of the core-shell GaN micropillars has been achieved using highly spatially resolved cathodoluminescence spectroscopy. CL mappings of the MOVPE grown GaN-bulk template, and the etched core-shell GaN heterostructures reveal a distinct blue-shift of the donor-bound exciton emission due to a strain relaxation.