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Title: Electric-field dependence of photocarrier generation efficiency of organic photoconductors

The electric-field dependence of photocarrier generation efficiency has been investigated in several different types of organic photoconductor for electrophotography to elucidate the controlling factors of light-to-electrical energy conversion. The rate-determining step in generating photocarriers has been considered to be the charge transfer between two neighboring molecules. Overall photocarrier generation efficiency has been determined using the charge transfer velocity at the rate-determining step as a function of electric-field-dependent activation energy, which is influenced by the symmetry factor α and the energy gap ΔE. The formula used successfully fits the experimental data for different types of organic photoconductor over a wide field strengths range. From the fitting results of high-sensitivity photoconductors, the zero-field activation energy is small and the reactant lifetime is long. In addition, ΔE is zero, which implies that the hole-electron interaction in the reactant is negligible at the rate-determining step. In contrast, for low-sensitivity photoconductors, the zero-field activation energy is large and the reactant lifetime is short; however, ΔE < 0 and α > 0.5, which suggest that the hole-electron interaction is not negligible. Consequently, the proposed formula well explains the electric-field dependence of photocarrier generation efficiency on the basis of its controlling factors.
Authors:
 [1]
  1. Department of Materials Science and Technology, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188 (Japan)
Publication Date:
OSTI Identifier:
22413230
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACTIVATION ENERGY; CHARGE CARRIERS; ELECTRIC FIELDS; ELECTRONS; ENERGY CONVERSION; ENERGY GAP; HOLES; LIFETIME; MOLECULES; PHOTOCONDUCTORS; SENSITIVITY; SYMMETRY; VELOCITY; VISIBLE RADIATION