Thermally stimulated luminescence and conductivity of doped Ar solids

Abstract

Solid Ar samples doped with the noble metal atoms Au or Ag as well as with 0953-8984/8/20/014/img10 molecules have been exposed to synchrotron and x-ray irradiation. Impurity trapping of excitons generated by the irradiation partly led to an ionization; the impurities formed deep traps for one type of charge carrier, the complementary ones were promoted into band states and subsequently captured into shallow traps. These charge carriers could be thermally released giving rise to thermally stimulated luminescence (TSL) and conductivity (TSC) signals, which were recorded simultaneously. The glow curves of both, TSL and TSC, clearly revealed the existence of intrinsic and extrinsic electron traps. Using a step-like temperature increase it could be demonstrated that traps exist with a broad distribution of binding energies. A first-order kinetics model was developed to extract binding energies from the temperature dependence of the thermally stimulated luminescence.