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. Room temperature photoluminescence of the microdisks manifests a very high near-band-edge (NBE) emission peak in the UV region and a minor defect peak in the visible region. The excitonic emission of the microdisks was studied using the low-temperature photoluminescence down to 83 K, which reveals a surface exciton peak in the NBE region and well fitted higher-order phonon replicas.

Automated summary

This study investigated the excitonic properties of highly crystalline ZnO hexagonal microdisks grown by chemical vapor deposition, indicating that a negative catalyst like chlorine can suppress crystal growth along the (0001) direction. A qualitative model was proposed to explain the layer-by-layer growth mechanism of the microdisks, with room temperature photoluminescence showing a high NBE emission peak and a minor defect peak. Low-temperature photoluminescence down to 83 K revealed surface exciton peaks in the NBE region and well-fitted higher-order phonon replicas.