High Speed Mid-Infrared Interband Cascade Photodetector Based on InAs/GaSb Type-II Superlattice

TL;DR

This paper reports a high-speed mid-infrared photodetector based on InAs/GaSb superlattice with a 2.4 GHz bandwidth and discusses its limitations, advancing understanding of MWIR detector performance at room temperature.

Contribution

The study introduces a novel InAs/GaSb superlattice interband cascade photodetector with a 2.4 GHz bandwidth at room temperature, highlighting its high-speed capabilities.

Findings

3 dB cutoff frequency of 2.4 GHz at 300 K

50% cutoff wavelength at ~5.3 μm

Performance limitations discussed

Abstract

High speed mid-wave infrared (MWIR) photodetectors have applications in the areas such as free space optical communication and frequency comb spectroscopy. However, most of the research on the MWIR photodetectors is focused on how to increase the quantum efficiency and reduce the dark current, in order to improve the detectivity (D*), and the 3dB bandwidth performance of the corresponding MWIR photodetectors is still not fully studied. In this work, we report and characterize a MWIR interband cascade photodetector based on InAs/GaSb type-II superlattice with a 50% cutoff wavelength at ~5.3 um at 300 K. The 3 dB cutoff frequency is 2.4 GHz at 300 K, for a 40 {\mu}m circular diameter device under -5 V applied bias. Limitations on the detector high speed performance are also discussed.High speed mid-wave infrared (MWIR) photodetectors have applications in the areas such as free space optical communication and frequency comb spectroscopy. However, most of the research on the MWIR photodetectors is focused on how to increase the quantum efficiency and reduce the dark current, in order to improve the detectivity (D*), and the 3dB bandwidth performance of the corresponding MWIR photodetectors is still not fully studied. In this work, we report and characterize a MWIR interband cascade photodetector based on InAs/GaSb type-II superlattice with a 50% cutoff wavelength at ~5.3 um at 300 K. The 3 dB cutoff frequency is 2.4 GHz at 300 K, for a 40 um circular diameter device under -5 V applied bias. Limitations on the detector high speed performance are also discussed.