Cathodoluminescence Of Vapour-Synthesized Diamond

Cathodoluminescence of diamond films has been investigated in the range of 2.0-3.5 eV. The CL spectra of diamond films are very sensitive to impurities such as nitrogen and boron. The main emission peak occurs around 2.8 eV in the films where the content of these impurities are lowered. The shape and behaviour of the spectra of the films are very similar to those obtained in natural type IIa diamond. The boron doping to the films increases the CL intensity. The luminescence is explained by donor-acceptor pair recombination where the acceptor is substitutional boron. In the semiconducting film, electroluminescence has been observed at metal/diamond(p-type) interfaces for the first time. From the CL imaging study, (100) growth sectors of diamond particle are much more luminescent than (111) sectors. This result indicates that the introduction of impurity or defect during crystal growth differs in each sectors.