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  • Open Access

Spectral approach to electron emission analysis from heterogeneous surfaces

J. Ludwick1,2, G. Saiz3, L. Douillard3, T.C. Back1,*, and A. Sayir4

  • *Contact author: tyson.back.1@us.af.mil
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Phys. Rev. Applied 25, 044070 – Published 24 April, 2026

DOI: https://doi.org/10.1103/p1lh-79xp

Abstract

This study introduces a methodology to extract multiwork function distributions directly from thermally emitted electron distribution (ThEED) data, addressing the limitations of traditional Richardson–Laue–Dushman methods for heterogeneous thermal emission cathodes. This approach involves deconvolving measured thermally emitted electron distributions with an instrument response function (derived from a homogeneous sample) and then applying a steepest-descent algorithm to determine the relative contributions of various work functions, while also considering the impact of external electrostatic fields on patch field effects. The methodology is validated using single-phase Mayenite [Ca24Al28O64]4+(4e−), an electride material with spatially varying work functions, by comparing the predicted distributions with photoemission electron microscopy (PEEM) work function maps and Monte Carlo simulations. The results demonstrate excellent agreement between the predicted and measured work function distributions, highlighting the method’s accuracy in resolving surface heterogeneity. Furthermore, the technique is successfully applied to ThEED data taken at a characterized surface location, showing promise for analyzing complex emission patterns in thermal emission cathodes. This methodology eliminates the need for complementary, potentially spatially mismatched, surface characterization techniques, offering a powerful tool for understanding and designing advanced thermal emitters.

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Phys. Rev. Applied 25, 044070– Published 24 April, 2026
  • Received 22 August 2025
  • Revised 3 February 2026
  • Accepted 25 March 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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