UV hybrid photon detector based on GaN photocathodes and Si low gain avalanche diode

TL;DR

This paper introduces a hybrid photon detector combining GaN photocathodes and Si LGADs, achieving high quantum efficiency and low noise for single-photon detection at hundreds of MHz.

Contribution

First design and operational results of a GaN photocathode and Si LGAD hybrid photon detector with high efficiency and fast response.

Findings

Achieved single-photon sensitivity with high quantum efficiency.

Demonstrated operation at hundreds of MHz repetition rates.

Low noise characteristics suitable for scientific applications.

Abstract

Photon detectors featuring single-photon sensitivity play a crucial role in various scientific domains, including high-energy physics, astronomy, and quantum optics. Fast response time, high quantum efficiency, and minimal dark counts are the characteristics that render them ideal candidates for detecting individual photons with exceptional signal-to-noise ratios, at frequencies in the the range of hundreds of MHz. Here, we report on our first design and operational results on a Hybrid Photon Detector (HPD) that combines the high quantum efficiency of a Gallium Nitride (GaN) photocathode and the low noise characteristics of a Si-based Low-Gain Avalanche Diode (LGAD). This hybrid detection scheme has the potential to reach single-photon detection sensitivity with high quantum efficiency, low noise levels and capable of operating at hundreds of MHz repetition rates.