Analysis of quantum efficiency improvement in spin-polarized photocathode

Xiuguang Jin, Shunsuke Ohki, Tomoki Ishikawa, Atsushi Tackeuchi, Yosuke Honda

    Research output: Contribution to journalArticle

    5 Citations (Scopus)

    Abstract

    GaAs/GaAsP strain-compensated superlattices (SLs) were developed for spin-polarized photocathode applications. High crystal quality was maintained with SL thicknesses up to 720 nm (90-pairs); however, the quantum efficiency (QE) did not increase linearly with the SL thickness but became saturated starting from an SL thickness of 192 nm (24-pairs). Time-resolved photoluminescence measurements revealed that the carrier lifetime in the GaAs/GaAsP strain-compensated SL was as short as 20.5 ps at room temperature, which causes the elimination of photoexcited electrons before emission. A simulation based on a diffusion model was implemented to quantitatively evaluate the effect of the carrier lifetime on the QE. The simulation results were in good agreement with the experimental results and demonstrate that a carrier lifetime of over 120 ps is required for a two-fold improvement of the QE.

    Original languageEnglish
    Article number164501
    JournalJournal of Applied Physics
    Volume120
    Issue number16
    DOIs
    Publication statusPublished - 2016 Oct 28

    Fingerprint

    photocathodes
    carrier lifetime
    quantum efficiency
    electron emission
    superlattices
    elimination
    simulation
    photoluminescence
    causes
    room temperature
    crystals

    ASJC Scopus subject areas

    • Physics and Astronomy(all)

    Cite this

    Analysis of quantum efficiency improvement in spin-polarized photocathode. / Jin, Xiuguang; Ohki, Shunsuke; Ishikawa, Tomoki; Tackeuchi, Atsushi; Honda, Yosuke.

    In: Journal of Applied Physics, Vol. 120, No. 16, 164501, 28.10.2016.

    Research output: Contribution to journalArticle

    Jin, Xiuguang ; Ohki, Shunsuke ; Ishikawa, Tomoki ; Tackeuchi, Atsushi ; Honda, Yosuke. / Analysis of quantum efficiency improvement in spin-polarized photocathode. In: Journal of Applied Physics. 2016 ; Vol. 120, No. 16.
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