Photoconductivity of potassium colloids in KCl single crystals

Detailed photoconductivity spectra of potassium colloids in KCl single crystals are presented. A broad band peaked at ～2 eV, together with a small shoulder at ～1.3 eV are observed for crystals containing colloids with radii in the 20–500 Å range.The spectrum shape is essentially independent of temperature and colloid radius. On the other hand, the maximum photoconductivity yield depends on the colloid radius reaching a maximum value at about 60 Å.