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

Abstract

Hydrogen-vacancy related defect (H 1′) in chemical vapor deposition homoepitaxial diamond films has been investigated by electron paramagnetic resonance and cathodoluminescence. It is found that the concentration of H 1′ significantly decreases as the dilution (CH4 H2) ratio decreases. It is also confirmed that the intensity of free-exciton emission (Iex) increases as the CH4 H2 ratio decreases. The complementary relationship between Iex and H 1′ can be explained by considering that H 1′ acts as a nonradiative recombination center which reduces the lifetime of free exciton and Iex. The suppression mechanism of H 1′ is discussed by considering the balance between the growth rate and the annihilation rate of H 1′ in the subsurface region. © 2006 American Institute of Physics.