Excitonic properties of layer-by-layer CVD grown ZnO hexagonal microdisks.

We have investigated the excitonic properties of highly crystalline ZnO hexagonal microdisks grown by the chemical vapour deposition technique. It was observed that a suitable negative catalyst like chlorine suppresses the crystal growth along the (0001) direction. We propose a qualitative model for the experimentally observed layer-by-layer growth mechanism of the microdisks.