Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1669167 | Thin Solid Films | 2010 | 5 Pages |
A high-quality ZnO epilayer was grown on the (0001) sapphire substrate by atomic layer deposition (ALD) and followed by high-temperature rapid thermal annealing (RTA). The layer-by-layer growth and low deposition temperature of ALD, as well as the RTA treatment, prevent the formation of columnar structures in the ZnO epilayer. A distorted ZnO layer at the ZnO/sapphire interface, which relaxes the misfit in ZnO leads to a low threading dislocation density in the ZnO epilayer. Optically-pumped stimulated emission was achieved with a low-threshold intensity of 153 kW/cm2 at room temperature. The good crystalline quality and low-threshold stimulated emission indicate that the ALD approach is appropriate for preparing high-quality ZnO epilayers.