Emission Properties of a Hybrid Metallized Diamond(001) Photocathode

TL;DR

This paper investigates the emission properties of a hybrid metallized diamond(001) photocathode, revealing how quantum efficiency and electron energy are influenced by material interfaces and phonon-assisted mechanisms, with implications for red-visible photocathodes.

Contribution

It introduces a novel hybrid metallized diamond(001) photocathode with detailed analysis of emission mechanisms and potential for high-efficiency red-visible photocathodes.

Findings

Quantum efficiency depends on photo-injection efficiency at the ohmic contact.

Mean transverse energy aligns with phonon-assisted emission mechanisms.

Emission observed from both conduction bands with different electron affinity states.

Abstract

The spectral emission characteristics of a proof-of-concept hybrid metallized diamond(001) photocathode are presented. The quantum efficiency (QE) is shown to be determined by the photo-injection efficiency across the ohmic contact at the back metallized face, whereas the mean transverse energy (MTE) of the photoemitted electrons is consistent with a (optical)phonon-assisted and momentum-resonant Franck-Condon mechanism [Phys. Rev. Applied 23, 054065 (2025)] following electron drift transport to the untreated diamond(001) front emission face. Emission is observed from both the lower and upper conduction bands of diamond with positive and negative electron affinity respectively. A potential route to the realization of a red-visible photocathode based on this concept with a sub-50meV MTE and a QE greater than 0.1% is discussed.