Coupling of the dissociative electron attachment resonances of CO 2 to anionic excitations in rare gas solids

Significant sharp enhancements (FWHM ≤ 0.5 eV) are observed in electron stimulated desorption O ^- yields, obtained from small quantities of CO ₂ physisorbed on thick rare gas substrate films. The enhancement are positioned 0.3-0.4 eV below the lowest substrate exciton energy, and are attributed to a coupling of the (electron plus exciton) core-excited anion resonances of the rare gas atoms to the dissociative temporary molecular anion states of the co-adsorbed CO ₂ at the solid's surface. This causes a transfer of the charge and excitation energy to the co-adsorbate.