High Responsivity in Molecular Beam Epitaxy (MBE) grown \b{eta}-Ga2O3 Metal Semiconductor Metal (MSM) Solar Blind Deep-UV Photodetector

TL;DR

This paper reports the development of high-responsivity, low-dark-current MSM photodetectors based on MBE-grown -Ga2O3, demonstrating state-of-the-art performance for solar blind deep-UV detection.

Contribution

It introduces a novel MBE growth process for -Ga2O3 MSM photodetectors with record responsivity and low dark current, advancing deep-UV photodetector technology.

Findings

Peak spectral responsivity > 1.5 A/W at 236-240 nm

Dark current < 10 nA at 20 V

Photo-to-dark current ratio > 10^3

Abstract

In this report, we demonstrate high spectral responsivity (SR) in MBE grown epitaxial \b{eta}-Ga2O3-based solar blind MSM photodetectors (PD). (-2 0 1)-oriented \b{eta}-Ga2O3 thin film was grown by plasma-assisted MBE on c-plane sapphire substrates. MSM devices fabricated with Ni/Au contacts in an interdigitated geometry were found to exhibit peak SR > 1.5 A/W at 236-240 nm at a bias of 4 V with a UV to visible rejection ratio > 105. The devices exhibited very low dark current < 10 nA at 20 V and showed no persistent photoconductivity (PPC) as evident from the sharp transients with a photo-to-dark current ratio > 103. These results represent the state-of-art performance for MBE-grown \b{eta}-Ga2O3 MSM solar blind detector.