Silicon Detector Arrays with Absolute Quantum Efficiency over 50% in the Far Ultraviolet for Single Photon Counting Applications

TL;DR

This paper presents silicon detector arrays with over 50% quantum efficiency in the ultraviolet range, achieved through advanced delta doping and AR coating techniques, enabling effective single photon counting.

Contribution

It introduces a novel combination of delta doping and atomic layer deposition for high-efficiency UV silicon detectors with minimal impact on dark current.

Findings

Over 50% external quantum efficiency in UV range

Near 100% internal quantum efficiency achieved

Dark current remains unchanged after processing

Abstract

We have used Molecular Beam Epitaxy (MBE)-based delta doping technology to demonstrate near 100% internal quantum efficiency (QE) on silicon electron-multiplied Charge Coupled Devices (EMCCDs) for single photon counting detection applications. Furthermore, we have used precision techniques for depositing antireflection (AR) coatings by employing Atomic Layer Deposition (ALD) and demonstrated over 50% external QE in the far and near-ultraviolet in megapixel arrays. We have demonstrated that other device parameters such as dark current are unchanged after these processes. In this paper, we report on these results and briefly discuss the techniques and processes employed.