低エミッタンス・短パルス半導体フォトカソードの開発

2013 Fiscal Year Annual Research Report

• Project/Area Number: 23760310
• Research Institution: Nagoya University
• Principal Investigator: 金 秀光 名古屋大学, 高等研究院, 特任助教 (20594055)
• Keywords: 半導体フォトカソード / 応答性

Research Abstract

半導体フォトカソードの応答性は、励起電子の拡散過程により決められる。速い応答性を得るためには、フォトカソードに内部電界を印加し、電子のトランジスタを速くする方法がある。申請者は活性層をAl0.2Ga0.8As層よりGaAs層まで、5つのステップに分けて、Alの組成を下げた。隣接した活性層にはバンドギャップの違いにより、界面に電界が生じる。
測定結果、傾斜型AlGaAs試料のデールはバルクAlGaAsのそれより明らかに短くなった。この効果は、拡散モデルに内部電界を組み合わせることで説明できる。内部電界は活性層の界面に生じ、界面での励起電子の分布を前に進ませる。前向きの電子分布は電子の拡散に有効であり、応答性が速くなる。内部電界は量子効率にも有効である。523 nm励起光において、傾斜型AlGaAsの量子効率は13%であり、バルクAlGaAsの8%の量子効率に比べ明らかな向上である。

Research Products

• [Journal Article] Precise measurement of residual strain in superlattice layers by nano-beam electron (2014)
  • Author(s): X.G. Jin, H. Nakahara, K. Saitoh, N. Tanaka, Y. Takeda,
  • Journal Title: Appl. Phys. Lett. Volume: 104 Pages: 113106
  • DOI: 10.1063/1.4869030
  • Peer Reviewed
• [Journal Article] Picosecond electron bunches from GaAs/GaAsP strained superlattice photocathode (2013)
  • Author(s): X.G. J in, S. Matsuba, Y. Honda, T. Miyajima, M. Yamamoto, T. Utiyama, Y. Takeda
  • Journal Title: Ultramicroscopy Volume: 130 Pages: 44-48
• [Journal Article] Phase-locking of oscillating images using laser-induced spin-polarized pulse TEM (2013)
  • Author(s): M. Kuwahara, Y. Nambo, S. Kusunoki, X.G. Jin, T. Nakanishi, K. Saitoh, H. Asano, T. Ujihara, Y. Takeda, T. Nakanishi, N. Tanaka
  • Journal Title: Microscopy Advance Access Volume: 62 Pages: 607-614
• [Journal Article] Temporal Response Measurements of GaAs-Based Photocathodes (2013)
  • Author(s): Y. Honda, S. Matsuba, X.G. Jin, T. Miyajima, M. Yamamoto, T. Uchiyama, M. Kuwahara,
  • Journal Title: Jpn. J. Appl. Phys Volume: 52 Pages: 086401
  • DOI: 10.7567/JJAP.52.086401
  • Peer Reviewed
• [Presentation] LEEM and AES study of negative electron affinity GaAs photocathode degradation process (2013)
  • Author(s): X.G. Jin, A. Cotta, G. Chen, A. N`Diaye, A. K. Schmid, Y. Takeda
  • Organizer: 9th International Symposium on Atomic Level Characterization for New Materials and Devices
  • Place of Presentation: Hawaii, USA
  • Year and Date: 20131202-20131206
• [Presentation] High performance spin-polarized photocathode using GaAs/GaAsP strain-compensated superlattice (2013)
  • Author(s): X.G. Jin, N. Yamamoto, A. Mano, M. Yamamoto, Y. Takeda
  • Organizer: The 2013 International Workshop on Polarized Sources, Targets & Polarimetry
  • Place of Presentation: The University of Virginia, USA
  • Year and Date: 20130909-20130913
• [Presentation] ovel development of very high brightness and highly spin-polarized electron gun with compact 3D spin manipulator for SPLEEM (2013)
  • Author(s): T. Koshikawa, T. Yasue, M. Suzuki, K. Tsuno, S. Goto, X.G. Jin and Y. Takeda
  • Organizer: IVC-19/ICSS-15 AND ICN+T
  • Place of Presentation: Paris, France
  • Year and Date: 20130909-20130913
• [Presentation] Nano-scale characterization of GaAsP/GaAs strained superlattice structures by nano-beam electron diffraction (2013)
  • Author(s): X.G. Jin, H. Nakahara, K. Saitoh, N. Tanaka, Y. Takeda
  • Organizer: 17th International Conference on Crystal Growth and Epitaxy
  • Place of Presentation: Poland
  • Year and Date: 20130811-20130816