A unique conducting state under UV-irradiation
(PHYSorg.com Chemistry)

A highly conducting state has been found in a molecular crystal under UV-irradiation. The state reversibly appears in accordance with UV-irradiation, but does not appear by any other method such as raising the temperature, which often induces metallic behavior in insulating molecular crystals. The UV-excited state exhibits conduction and magnetic behavior characteristic of metallic substances. The result suggests that there is an optically accessible, but thermally inaccessible, state of matter.