Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version

11-6-2012

Comments

Sahasrabuddhe, K., Schwede, J., Bargatin, I., Jean, J., Howe, R., Shen, Z., & Melosh, N. (2012). A model for emission yield from planar photocathodes based on photon-enhanced thermionic emission or negative-electron-affinity photoemission. Journal of Applied Physics, 112(9), 094907. doi: 10.1063/1.4764106

Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Abstract

A general model is presented for electron emission yield from planar photocathodes that accounts for arbitrary cathode thickness and finite recombination velocities at both front and back surfaces. This treatment is applicable to negative electron affinity emitters as well as positive electron affinity cathodes, which have been predicted to be useful for energy conversion. The emission model is based on a simple one-dimensional steady-state diffusion treatment. The resulting relation for electron yield is used to model emission from thin-film cathodes with material parameters similar to GaAs. Cathode thickness and recombination at the emissive surface are found to strongly affect emission yield from cathodes, yet the magnitude of the effect greatly depends upon the emission mechanism. A predictable optimal film thickness is found from a balance between optical absorption, surface recombination, and emission rate.

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Date Posted: 27 February 2013

This document has been peer reviewed.