Self-assembly of GaAs holed nanostructures by droplet epitaxy

We report on Ga nano‐droplets on GaAs(100) that are not stable under arsenic flux. Spontaneous evolution in shape leads to many interesting GaAs nanostructures. GaAs nano‐crystals shaped like lighted candles and square‐holed round coins are observed under different growth conditions. The underlying physics of the formation of these interesting nano‐structures can be understood in terms of GaAs growth under a uniform arsenic flux and a non‐uniform Ga supply from the Ga nano‐droplets. These novel shaped GaAs nanostructures, in an AlGaAs matrix, offer promising applications in optoelectronics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)