Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 80: GaN: Preparation and Characterization V (mainly Cathodoluminescence)
HL 80.8: Vortrag
Donnerstag, 29. März 2012, 13:00–13:15, ER 270
Cathodoluminescence microscopy and X-ray diffraction measurements of semipolar (1101) GaN structures with InGaN SQWs on patterned Si(001) substrate — •Christopher Karbaum1, Frank Bertram1, Sebastian Metzner1, Jürgen Christen1, Jürgen Bläsing1, Alois Krost1, Shujian Liu2, Vitaliy Avrutin2, Natalia Izyumskaya2, Ümit Özgür2, and Hadis Morkoç2 — 1Institute of Experimental Physics, Otto-von-Guericke-University Magdeburg, Germany — 2Depart. of Electrical and Computer Engineering, VCU, Richmond, USA
The optical and crystalline properties of GaN bars with (1101) faceted surfaces were investigated using spatially and spectrally resolved cathodoluminescence (CL) at liquid helium temperature and high resolution X-ray diffraction (HRXRD), respectively. Triangular-shaped GaN bars with semipolar (1101) facets and an InGaN LED structure atop were grown on a structured Si(001) substrate exhibiting V-shaped grooves aligned along Si[110]. In the c+-wing near the Si side facet the (D0,X) emission of GaN is shifted to lower energies (3.451 eV) due to tensile strain. Intense CL from basal plane stacking faults (BSF) at 3.424 eV can be found in the c−-wing. The CL from the top view reveals intense and broad InGaN emission with an inhomogeneous distribution of the peak energy on the micrometer-scale and emission maxima centered at about 2.48 eV and 3.10 eV. The temperature dependence of the above mentioned CL will be presented. HRXRD measurements indicate an orientation disorder of about one degree of the GaN bars in each direction.