Impact of superlattice size on quantum efficiency and polarization in MOCVD-grown strained GaAs/GaAsP photocathodes

A Adam Masters (Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,) G Greg Blume (Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,) S Sushil Poudel (Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,) J Joseph Michael Grames (Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,) M Matt Poelker (Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,) M Marcy Stutzman (Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,) S Stephen Polly (Rochester Institute of Technology 3 , 1 Lomb Memorial Drive, Rochester, New York 14623,) S Seth M. Hubbard (Rochester Institute of Technology 3 , 1 Lomb Memorial Drive, Rochester, New York 14623,) S Sylvain Marsillac (Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,) M Matt Grau (Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,)

Abstract

Strained superlattice GaAs photocathodes are crucial for providing high photocurrent beams of spin-polarized electrons at several accelerator facilities including the Continuous Electron Beam Accelerator Facility at Thomas Jefferson National Accelerator Facility and the future Electron–Ion Collider at Brookhaven National Laboratory. In this work, we study the effects of varying the number of superlattice pairs on the polarization and photocurrent of the photocathodes. We observe a saturation in quantum efficiency beyond 30 pairs, with additional layers yielding minimal photocurrent improvement while noticeably reducing the polarization of the beam.

Article Details

Volume / Issue Vol. 128, Issue 8
Published February 23, 2026
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (10)

A

Adam Masters

Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,

G

Greg Blume

Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,

S

Sushil Poudel

Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,

J

Joseph Michael Grames

Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,

M

Matt Poelker

Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,

M

Marcy Stutzman

Thomas Jefferson National Accelerator Facility 2 , 12000 Jefferson Avenue, Newport News, Virginia 23606,

S

Stephen Polly

Rochester Institute of Technology 3 , 1 Lomb Memorial Drive, Rochester, New York 14623,

S

Seth M. Hubbard

Rochester Institute of Technology 3 , 1 Lomb Memorial Drive, Rochester, New York 14623,

S

Sylvain Marsillac

Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,

M

Matt Grau

Old Dominion University 1 , 5115 Hampton Blvd, Norfolk, Virginia 23529,