Effect of diamond film quality on tungsten related photoluminescence peaks

We have studied a series of polycrystalline diamond films of various qualities grown by are jet chemical vapor deposition method. We have used continuous wave photoluminescence (PL) to study the intensity, width and emission energy of defects, and study the correlation of these parameters to the quality of the diamond films, Recently, it has been proposed that impurities are more easily incorporated into highly defective films, and thus the defect PL may be used to determine impurity concentration in the films. We find that the intensity of the PL from the 1.735 eV center is easily affected by the quality and may he quenched in poor duality samples, and thus it is not an appropriate marker for defect concentration, We find the center with an emission line at 1.805 eV to be a better candidate for being used as a marker for defect concentration. This center is observed in different quality samples, and its line width and emission energy are not affected by film quality. (C) 1997 American Institute of Physics. [S0003-6951(97)04551-8].