POSITRON LIFETIME INVESTIGATIONS OF DIAMOND FILMS

Positron lifetime investigations on B-doped and undoped chemical vapor deposition diamond films have shown that B-doping at 500 ppm almost completely removes vacancies from the film. The 1.68 eV photo luminescence (PL) line is also removed. For undoped films, large concentrations (almost-equal-to 10(18) cm-3) of Vacancy clusters (approximately 6 vacancies) and mono- or divacancies are observed. Small observable effects arising. from annealing up to 1100-degrees-C could be found in both B-doped or undoped films. There is no correlation between the width of the 1.68 eV PL line and the vacancy concentration.