High quantum efficiency S-20 photocathodes in photon counting detectors

TL;DR

This paper introduces a new series of high QE S-20 photocathodes with tunable spectral response, low dark counts, and fast response, optimized for photon counting applications in various spectral regions.

Contribution

Developed a new series of high QE S-20 photocathodes with spectral tunability, low dark count rates, and fast response suitable for photon counting detectors.

Findings

QE exceeds 30% at maximum response

Dark count rate as low as 30 Hz/cm² at room temperature

Effective in photon counting detectors like MCP photomultiplier tubes

Abstract

Based on conventional S-20 processes, a new series of high quantum efficiency (QE) photocathodes has been developed that can be specifically tuned for use in the ultraviolet, blue or green regions of the spectrum. The QE values exceed 30% at maximum response, and the dark count rate is found to be as low as 30 Hz/cm$^2$ at room temperature. This combination of properties along with a fast temporal response makes these photocathodes ideal for application in photon counting detectors, which is illustrated with an MCP photomultiplier tube for single and multi-photoelectron detection.