ATMOSPHERE SENSITIVE PHOTOCONDUCTIVITY OF C60 THIN-FILMS PREPARED IN HIGH-VACUUM

It has been found that C60 thin films prepared by vapor deposition in high vacuum and measured in situ without exposure to air exhibit a high photocarrier generation quantum efficiency in excess of 50%. The photocurrent and dark current, however, decrease dramatically on the introduction of oxygen into a sample chamber, indicating very high sensitivity of C60's electrical properties to oxygen, the cause of which can be ascribed to carrier trapping or excited state quenching by oxygen.