Long-decay-time photoconductivity in highly disordered carbon fibers

Journal Article · Tue Oct 15 04:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.8256· OSTI ID:5159526

Kuriyama, K; Dresselhaus, M S ^[1]

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1. Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts (USA)

A photoconductivity with a rather long decay time ({congruent}0.3 s at 290 K) is observed in a carbon material that is characterized by its huge specific surface area (1000 m{sup 2}/g). The decay time is temperature dependent at low temperatures ({lt}100 K) with a small activation energy (3--5 meV), and is also dependent on the illumination power. A decrease in the mobility of the carriers during the illumination is strongly suggested. The relaxation of dangling bonds on the large surface area is proposed as the mechanism to screen the Coulomb attraction among the photocarriers and to build a recombination barrier, resulting in the long decay time. This photoconductivity is considered to be an effect analogous to the persistent photoconductivity in semiconductors, although some apparent differences are also observed.

• OSTI ID: 5159526
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:15; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ACTIVATION ENERGY
ADSORPTION
CARBON FIBERS
CARRIER LIFETIME
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY
FIBERS
LIFETIME
MATERIALS
PHOTOCONDUCTIVITY
PHYSICAL PROPERTIES
RELAXATION
SEMICONDUCTOR MATERIALS
SORPTION
TEMPERATURE DEPENDENCE