PHOTOINDUCED CURRENT TRANSIENT SPECTROSCOPY OF BORON-DOPED DIAMOND

A Schottky device fabricated on a natural type 2b diamond was characterized using photoinduced current transient spectroscopy (PICTS). A trapping level, presumed to be due to boron, with an activation energy of 0.29 eV was found from PICTS. Resistance measurements on the same device produced an activation energy of 0.38 eV. The two methods, while being described by the same exponential temperature dependence, have prefactors with different physical origins. Since the activation energy measured by PICTS is proportional to sigma(eff)e(-E/kT), the difference in the measured values could be attributed to a temperature dependence in the ''effective'' hole capture cross-section sigma(eff). This report also demonstrates the potential of PICTS in identifying an electrically active trap in a sample whose high series resistance renders it difficult to characterize using capacitance based methods.