title: Storage of an electric field for photocurrent generation in ferroelectric-functionalized organic devices.
abstract: Organic optoelectronic devices are usually driven by the electric field generated from an electrode potential difference or bias voltage. Although poled ferroelectric domains may produce oriented stray fields, few efforts have been made to utilize them for photocurrent generation in organic devices. Here we show that large net fields caused by incomplete screening during ferroelectric polarization, and which can be 'restored' by short voltage pulses, can facilitate exciton dissociation in organic semiconductors. The oriented fields, comparable with that produced by an electrode potential difference (1~10 MV m(-1)), here are found to be responsible for the photocurrent in our devices. A prototype for an organic photodetector driven by such stray fields is demonstrated. The photoresponsivity, without any optimization, can achieve ~0.1 mA W(-1). This study provides a different operation principle for the generation of photocurrent in organic optoelectronic devices. Furthermore, the polarity-tunable photoresponse may lead to new photoresponsive memory devices.
authors.affiliation: 1] Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan [2] Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China.
authors.forename: Laigui
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Simon
authors.initials: S
authors.lastname: Dalgleish
authors.affiliation: Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Michio M
authors.initials: MM
authors.lastname: Matsushita
authors.affiliation: Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yoshikawa
authors.affiliation: 1] Department of Chemistry and Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan [2] CREST, JST, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Awaga