High-Density Nanosecond Charge Trapping in Thin Films of the Photoconductor ZnODEP
(1993)
Journal - Science
Abstract :
An electrooptical memory effect is observed with solid thinfilms of the photoconductor zinc-octakis(-decoxyethyl) porphyrin(ZnODEP) sandwiched between two optically transparent electrodes.Upon irradiation with the simultaneous application of an electricfield, electron-hole pairs are generated and separated withinthe photoconductive layer. These electron-hole pairs become"frozen" within the films when the irradiation is interrupted.These trapped charges can be released by irradiation of thecell, resulting in a transient short-circuit photocurrent. Nocross talk between adjacent memory elements separated by 0.2micrometer (a density of 3 gigabits per square centimeter) wasdetected. The charge storage system is robust and nonvolatile.The response time for the write-read beam is in the subnanosecondrange, and no refreshing is required for long-term retentionof trapped charges.
Photooxidation of Anthracene on Atmospheric Particulate Matter
(1979)
Journal - Science
Abstract :
Anthracene that has been dispersed into atmospheric particulatematter is photooxidized to an array of products reminiscentof oxidation by singlet oxygen in the solution phase. Photooxidationis a more important degradative pathway under ambient conditionsthan ozonation. Significant disappearance of anthracene alsooccurs by pathways not involving oxygenation.