Density effect on structures in photoconductivity excitation spectra of supercritical xenon doped with anthracene molecules

Abstract

Photoconductivity excitation spectra of liquid 2,2-dimethylbutane (2,2-DMB) and supercritical xenon doped with anthracene were measured at room temperature in an attempt to study the nature of the structure observed above the ionization threshold. For anthracene/Xe systems, spectra were measured isothermally as a function of fluid density N. Structures are observed at nearly the same energies for both anthracene/liquid 2,2-DMB and for anthracene/Xe system at N= 8 × 10 21 cm −3. The density dependence of the structures for the anthracene/Xe systems was interpreted as due to the shift in energy by the same mechanism which gives rise to the shift in the photoconductivity threshold.