A free-standing nanopillar with a diameter of 300 nm, and a height of 2 urn is successfully demonstrated by focused ion beam milling. The measured micro-photoluminescence (μ-PL) from the embedded InGaN/GaN multiple quantum wells shows a blue shift of 68 meV in energy with a broadened full-width at half maximum, ~200meV. Calculations based on the valence force field method suggest that the spatial variation of the strain tensors in the nanopillar results in the observed energy shift and spectrum broadening. Moreover, the power-dependent μ-PL measurement confirms that the strain-relaxed emission region of the nanopillar exhibits a higher radiative recombination rate than that of the as-grown structure, indicating great potential for realizing high-efficiency nano devices in the UV/blue wavelength range.
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|State||Published - 1 Dec 2008|
|Event||Optoelectronic Materials and Devices III - Hangzhou, China|
Duration: 27 Oct 2008 → 30 Oct 2008
- Focused ion beam
- Strain relaxation