Nitrogen-induced defects in ZnO : N grown on sapphire substrate by gas source MBE

Abstract

Nitrogen-doped ZnO layers were grown on sapphire substrates by radical source molecular beam epitaxy by simultaneously introducing O 2 and N 2 via a RF radical source. Reflection high-energy electron diffraction and X-ray diffraction measurements revealed that high N 2/O 2 flow ratios induced growth twins into the ZnO layer. A nitrogen-doped ZnO fabricated using a N 2/O 2 flow ratio of 10% was found to have a chemical nitrogen concentration of 1×10 19 cm −3. However, type conversion from n-type to p-type did not occur while large nitrogen incorporation was observed to induce extended defects.