Hydrogen-vacancy related defect in chemical vapor deposition homoepitaxial diamond films studied by electron paramagnetic resonance and cathodoluminescence

摘要

Hydrogen-vacancy related defect (H1') in chemical vapor deposition homoepitaxial diamond films has been investigated by electron paramagnetic resonance and cathodoluminescence. It is found that the concentration of H1' significantly decreases as the dilution (CH_4/H_2) ratio decreases. It is also confirmed that the intensity of free-exciton emission (I_(ex)) increases as the CH_4/H_2 ratio decreases. The complementary relationship between I_(ex) and H1' can be explained by considering that H1' acts as a nonradiative recombination center which reduces the lifetime of free exciton and I_(ex). The suppression mechanism of H1' is discussed by considering the balance between the growth rate and the annihilation rate of H1' in the subsurface region.