著者

Ootsuka Teruhisa Suemasu Takashi Chen Jun Sekiguchi Takashi Hara Yoshiaki

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.92, no.19, pp.192114, 2008-05

被引用文献数

14

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We have evaluated the lifetime and diffusion length of photogenerated minority carriers (holes) in single-crystalline n-type beta-FeSi2 bulk grown by chemical vapor transport. The diffusion length measured by optical-beam-induced current agreed well with that measured by electron-beam-induced current, that is, 51 and 38 µm, respectively, for samples annealed at 800 °C for 8 h. The decay curve of photoconductivity obtained by 1.31 and 1.55 µm light pulses was well fitted by assuming a carrier lifetime of approximately a few microseconds. The mobility of photogenerated minority carriers was estimated to be approximately 200–360 cm2/V s from the measured lifetime and diffusion length.

著者

Ootsuka Teruhisa Suemasu Takashi Chen Jun Sekiguchi Takashi

出版者

American Institute of Physics

雑誌

APPLIED PHYSICS LETTERS (ISSN:00036951)

巻号頁・発行日

vol.92, no.4, pp.042117, 2008-01

被引用文献数

13 15

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We have evaluated the diffusion length of minority carriers (holes) in single-crystalline n-type beta-FeSi2 bulk grown by chemical vapor transport by means of electron-beam-induced current (EBIC) technique in the edge-scan configuration. The EBIC line-scan data showed a clear exponential dependence of distance from the Al electrode. The diffusion length was estimated to be 20 µm at room temperature, and increased upon high-temperature annealing, reaching approximately 30 µm after annealing at 800 °C for 8 h. This result explained the improvement of photoresponsivity in the Al/n-beta-FeSi2 Schottky diodes by high-temperature annealing.

著者

Ootsuka Teruhisa Fudamoto Yasunori Osamura Masato Suemasu Takashi Makita Yunosuke Fukuzawa Yasuhiro Nakayama Yasuhiko

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.91, no.14, pp.142114, 2007-10

被引用文献数

23 25

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We have clearly observed photoresponse properties in an Al/n-beta-FeSi2 structure using beta-FeSi2 single crystals grown by chemical vapor transport. A photocurrent is observed for photons with energies greater than 0.68 eV. It increases sharply with increasing photon energy and attains a maximum at approximately 0.95 eV (1.31 µm). The photocurrent originated from the photoexcited electrons in the Al and the band-to-band photoexcited carriers in the beta-FeSi2 located under the Al contact. The photoresponsivity increased upon high-temperature annealing, reaching 58 mA/W at 0.95 eV after annealing at 800 °C for 8 h.