Resonance Raman and photoluminescence investigations of micro-twins in homoepitaxially grown chemical vapor deposited diamond

Resonance Raman and photoluminescence (PL) investigations of the {100}[111] penetration twin that forms during homoepitaxial diamond growth on (100) diamond substrates by microwave plasma chemical vapor deposition is reported on. A homoepitaxially grown diamond film of 0.13 mm thickness and 1.6 mm diameter was studied with blue (457.9 nm), green (514.5 nm), and red (647.1 nm) laser excitation. The amorphous carbon incorporated in the twin crystal shows resonance Raman enhancement with 647.1 nm excitation. PL spectroscopy reveals increased incorporation of nitrogen-vacancy (N-V) and nitrogen di-vacancy (N-V-2) defects in the twin as well as a new defect not observed in the bulk of the film. The present studies show that once the micro-twins are nucleated they form a preferential site for the incorporation of amorphous carbon and other nitrogen-based defects. (C) 1997 American Institute of Physics.