Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 97: Quantum Dots and Wires: Optical Properties IV (mainly Nitrides)

HL 97.6: Vortrag

Freitag, 30. März 2012, 11:15–11:30, ER 270

µ-Photoluminescence of GaN nanowires with different diameters and pitches grown by selective-area epitaxy on Si substrates — •Christian Hauswald¹, Tobias Gotschke¹, Oliver Brandt¹, Namil Koo², Jung Wuk Kim², Raffaella Calarco¹, Lutz Geelhaar¹, and Henning Riechert¹ — ¹Paul-Drude-Institut für Festkörperelektronik, Berlin — ²AMO GmbH, Aachen

Selective-area growth (SAG) of nanowires (NWs) by molecular beam epitaxy constitutes an important step towards uniform III-V NW arrays on Si. A homogeneous size and a controlled position are desirable for processing NWs into optoelectronic devices with predictable characteristics. In this work, we study the influence of different diameters and pitches of selectively grown NWs on their optical properties.

We use µ-photoluminescence (µ-PL) to investigate GaN NWs grown in pre-patterned holes defined by electron beam lithography in a SiO_x-mask. The holes have various shapes (hexagons, triangles, and squares) with diameters and periods in the range of 30–300 nm and 0.3–3.0 µm, respectively. All investigated NW arrays have been grown side by side on the same sample to ensure similar growth conditions. We compare the µ-PL spectra and integrated intensities of various NW diameter and pitch configurations and discuss the spatial homogeneity.

Finally, the coupling of light with GaN NWs fabricated using different mask geometries is simulated with a finite-element software to gain insight into the effects of the in-plane light propagation in SAG NW arrays. The potential of these ordered GaN NW arrays to form a photonic crystal is explored.