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Title: Transport Mechanisms in Polarized Semiconductor Photocathodes

Abstract

We investigated the effect of an accelerating field on the spin polarization of photogenerated electrons in a 100nm thick GaAs based photocathode active region. By decreasing the transport time of the electrons and the number of scattering events that cause depolarization, we expected to increase the polarization as was indicated by Monte Carlo simulations of the scattering and transport time statistics of the electrons. A tungsten (W) grid was deposited on the cathode surface to provide a uniform voltage distribution across the cathode surface. The metal grid formed a Schottky contact with the semiconductor surface. The bias voltage was primarily dropped at the metal semiconductor interface region, which is the cathode active region. For positive surface bias, the accelerating voltage not only increased the polarization, but it also enhanced the quantum efficiency of the photocathode. Preliminary results verify the bias effect on both quantum efficiency and polarization by a factor of 1.8 and 1% respectively.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
896723
Report Number(s):
SLAC-PUB-12261
TRN: US200704%%51
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Contributed to 17th International Spin Physics Symposium (SPIN06), Kyoto, Japan, 2-7 Oct 2006
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; PHOTOCATHODES; DEPOLARIZATION; POLARIZATION; QUANTUM EFFICIENCY; SCATTERING; SPIN; STATISTICS; GALLIUM ARSENIDES; ELECTRON TRANSFER; TUNGSTEN; Accelerators,ACCPHY

Citation Formats

Ioakeimidi, K., Brachmann, A., Clendenin, J.E., Garwin, E.L., Kirby, R.E., Maruyama, T., Prescott, C.Y., /SLAC, Prepost, R., and /Wisconsin U., Madison. Transport Mechanisms in Polarized Semiconductor Photocathodes. United States: N. p., 2006. Web.
Ioakeimidi, K., Brachmann, A., Clendenin, J.E., Garwin, E.L., Kirby, R.E., Maruyama, T., Prescott, C.Y., /SLAC, Prepost, R., & /Wisconsin U., Madison. Transport Mechanisms in Polarized Semiconductor Photocathodes. United States.
Ioakeimidi, K., Brachmann, A., Clendenin, J.E., Garwin, E.L., Kirby, R.E., Maruyama, T., Prescott, C.Y., /SLAC, Prepost, R., and /Wisconsin U., Madison. Mon . "Transport Mechanisms in Polarized Semiconductor Photocathodes". United States. doi:. https://www.osti.gov/servlets/purl/896723.
@article{osti_896723,
title = {Transport Mechanisms in Polarized Semiconductor Photocathodes},
author = {Ioakeimidi, K. and Brachmann, A. and Clendenin, J.E. and Garwin, E.L. and Kirby, R.E. and Maruyama, T. and Prescott, C.Y. and /SLAC and Prepost, R. and /Wisconsin U., Madison},
abstractNote = {We investigated the effect of an accelerating field on the spin polarization of photogenerated electrons in a 100nm thick GaAs based photocathode active region. By decreasing the transport time of the electrons and the number of scattering events that cause depolarization, we expected to increase the polarization as was indicated by Monte Carlo simulations of the scattering and transport time statistics of the electrons. A tungsten (W) grid was deposited on the cathode surface to provide a uniform voltage distribution across the cathode surface. The metal grid formed a Schottky contact with the semiconductor surface. The bias voltage was primarily dropped at the metal semiconductor interface region, which is the cathode active region. For positive surface bias, the accelerating voltage not only increased the polarization, but it also enhanced the quantum efficiency of the photocathode. Preliminary results verify the bias effect on both quantum efficiency and polarization by a factor of 1.8 and 1% respectively.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Dec 18 00:00:00 EST 2006},
month = {Mon Dec 18 00:00:00 EST 2006}
}

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