Optical absorption analysis on diamond crystals modified by H2+ implantation and subsequent annealing

The optical absorption analysis on synthetic diamond irradiated by molecular hydrogen ions (H2+) with 40 keV, 1015-1017 H/cm2, at 100 K, showed that the absorption coefficient (α) of modified layer in UV-VIS range was increased with the implanted dose and decreased with thermal annealing. While its relative optical band gap (Er,opt) was decreased with ion fluence and proportional to the annealing temperature. The possible microstructure of atomic coordination for as-implanted and subsequent annealing samples was discussed tentatively. In addition the optical inhomogeneity of the type Ib diamond has been revealed by absorption topograph at λ=430 nm. (author)