Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 55: GaN: preparation and characterization II
HL 55.5: Vortrag
Freitag, 29. Februar 2008, 11:30–11:45, ER 164
Properties of GaN-based thin film LEDs grown by MOVPE in dependence on the Si substrate orientations — •F. Schulze1, A. Dadgar1,2, S. Fritze1, J. Blaesing1, M. Wieneke1, A. Diez1, and A. Krost1,2 — 1Institute of Experimental Physics, Otto-von-Guericke-University, 39016 Magdeburg, Germany — 2Azzurro Semiconductors AG, Universitätsplatz 2, 39106 Magdeburg, Germany
The use of silicon as a substrate for GaN-based optoelectronic devices offers many advantages in terms of cost reduction and large size availability. For an optimization of the optical output performance, a subsequent delamination of the silicon substrates may be very helpful due to the absorbing properties of silicon in the range of visible light. Mechanical abrasion and chemical etching are a usual approach to obtain thin film LEDs on specular carriers with a good thermal conductivity. However, the crystallographic orientation of silicon strongly influences the abrasion resistance and the chemical etching rate. Therefore, GaN based LED structures were grown by MOVPE on different substrate orientations as Si(111), Si(011), and Si(001). We report on the quality of GaN-based devices in dependence on these surfaces. The influence of the thinning process will be discussed comparing the crystallographic properties of the device structures analysed by x-ray diffraction techniques. Furthermore, the impact of the different surface orientations on optical properties of the LEDs were analysed by electro- and cathodoluminescence.