Hole traps in natural type IIb diamond

Hole traps in natural type IIb diamond have been characterized with Schottky diodes using thermal and optical techniques. The Schottky diode capacitance variation with time was used to determine the detrapping rate of holes. For reverse-biased Schottky diodes the rate was found to be independent of both electric field from 0 to 3.6×10⁵ V cm^-1, and temperature from -25 to 102°C. Optical radiation below 1.4 eV (>890 nm) has no measurable effect on the detrapping rate, while the rate increases with decreasing wavelength below 870 nm, We speculate that the traps are caused by impurities, possibly nitrogen aggregates, distributed over an energy range 1.4-4 eV above the valence band