Low-temperature positron transport in semi-insulating GaAs

Article

关键词: MONTE-CARLO CALCULATIONS;    MONOENERGETIC POSITRONS;    KEV ELECTRON;    DIFFUSION;    SURFACES;    MOBILITY;    SI;    INTERFACE;    SOLIDS;    ANNIHILATION;   

DOI  :  10.1103/PhysRevB.55.9897

来源: SCIE

【 摘 要 】

Positron diffusion and drift in semi-insulating (SI) GaAs in the temperature range of 50-309 K were studied by the slow-positron beam technique. Both the temperature-dependent positron diffusion coefficient and positron mobility were measured independently using the method reported recently [Y. Y. Shan et al., Phys. Rev. B 54, 1982 (1996)]. The experimental results are consistent with the Einstein relation. The diffusion coefficient and mobility approximately follow D+(T) = 9400T(-beta) cm(2) s(-1), and mu(+)(T) = 10(8) x T-sigma cm(2) V-1 s(-1), with beta = 1.5+/-0.1, and sigma = 2.5+/-0.2, respectively in the temperature range of 50-300 K. The results are consistent with scattering from optical-phonon modes as the dominant scattering process for positron transport in GaAs (SI) in this temperature range. No trapped positron states were observed to 50 K.

【 授权许可】

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