The QE numerical simulation of PEA semiconductor photocathode

TL;DR

This paper develops a quantum efficiency model for PEA semiconductor photocathodes, incorporating multiple physical factors, and validates it through theoretical calculations matching experimental data at 532nm.

Contribution

It constructs a comprehensive integral equation for QE of PEA photocathodes based on a three-step model, considering various physical influences and validating with experimental data.

Findings

The theoretical QE aligns with experimental results at 532nm.

Factors like photon energy and electric field significantly affect QE.

Discrepancies between theory and experiment are analyzed.

Abstract

Several kinds of models have already been proposed for explaining the photoemission process. The exact photoemission theory of semiconductor photocathode was not well established after decades of research. In this paper an integral equation of quantum efficiency (QE) is constructed to describe the photoemission of positive electron affinity (PEA) semiconductor photocathode based on three-step photoemission model. The influences of forbidden gap, electron affinity, photon energy, incident angle, degree of polarization, refractive index, extinction coefficient, initial/final electron energy, relaxation time and external electric field on the QE of PEA semiconductor photocathode are taken into account. In addition, a computer code is also programmed to calculate the QE of K2CsSb photocathode theoretically at 532nm wavelength, the result is in line with the experimental value by and large. What are the reasons caused to the distinction between the experimental measuring and theoretical QE are discussed.