Journal of Physical Chemistry & Biophysics
Open Access
ISSN: 2161-0398
ISSN: 2161-0398
E Calleja1, A Bengoechea-Encabo1, S Albert1, M A Sanchez-Garc�?a1, D Lopez-Romero1, A Trampert2, U Jahn2, F Bertram3 and J Christen3
1University Polit�?©cnica, Spain 2Paul-Drude-Institut, Germany 3Otto-von-Guericke-University Magdeburg, Germany
Posters-Accepted Abstracts: J Phys Chem Biophys
New advances on Selective Area Growth (SAG) of InGaN/GaN nanostructures by plasma-assisted MBE on GaN/sapphire templates and Si (111) substrates are presented. Both, axial and core-shell structures are considered. Very intense green electroluminescence is achieved on axial nanoLEDs grown on Si(111). Blue emission is observed in core-shell nanoLEDs. First results on core-shell InGaN/GaN structures grown by MBE on GaN templates are also presented. Cylindrical micro-rods are etched down by ICP from a 3 micron thick GaN/sapphire template. GaN and InGaN layers are then grown both in axial and radial directions so that the initial GaN cylinder is covered in a conformal way. Hexagonal symmetry is fully recovered once the GaN shell layer is grown. Potential advantages of this core-shell structure as compared to the axial one are twofold: The increase of emission surface (lateral area) and the absence of internal electric fields (m-plane). The crystal perfection is much better than that of 2D InGaN films of similar in % composition. Ordered arrays of GaN and InGaN axial nanostructures are grown on non-polar and semi-polar directions and subsequently merged into a continuous film to produce high quality pseudo substrates. Results show that in both cases the resulting films exhibit a very strong luminescence, orders of magnitude higher that from the substrate used. Semi-polar GaN templates have a huge density of stacking faults (SFs) most of them are filtered upon coalescence of the nanostructures grown on top. In all cases there is a preferential growth direction along the c-plane (0001). PL and spatially resolved CL measurements on individual nanostructures, polar, non-polar, or semi-polar show that the incorporation depends strongly on the crystal plane considered.
Email: calleja@isom.upm.es