Transient photoconductivity spectroscopy of polycrystalline diamond films

Photoexcitation spectra of nonequilibrium charge carriers in polycrystalline diamond films were measured in the visible region (430 — 690 nm) by the contact-less transient photoconductivity technique with a tunable optical parametric oscillator. Preliminary irradiation of samples by intense UV laser pulses resulted in the redistribution of the population of deep trap levels and was accompanied by substantial long-term enhancement of photoconductivity in the spectral band at 2 eV.