InGaAs based heterojunction phototransistors: Viable solution for high-speed and low-noise short wave infrared imaging

Mohsen Rezaei, Min Su Park, Cobi Rabinowitz, Chee Leong Tan, Skylar Wheaton, Melville Ulmer, Hooman Mohseni*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Highly sensitive and fast imaging at short-wavelength infrared (SWIR) is one of the key enabling technologies for the direct-imaging of habitable exoplanets. SWIR imaging systems currently available in the market are dominated by imagers based on InGaAs PIN photodiodes. The sensitivity of these cameras is limited by their read-out noise (RON) level. Sensors with internal gain can suppress the RON and achieve lower noise imaging. In this paper, we demonstrate a SWIR camera based on 3D-engineered InP/InGaAs heterojunction phototransistors with responsivities around 2000 A/W which provides a shot-noise limited imaging sensitivity at a very low light level. We present the details of the semiconductor structure, the microfabrication, and the heterogeneous integration of this camera. The low capacitance pixels of the imager achieve 36 electron effective RON at frame rates around 5 kilo-frames per second at an operating temperature of 220 K and a bias voltage of 1.1 V. This is a significant step toward achieving highly sensitive imaging at SWIR at high frame rates and noncryogenic operating temperatures. Based on the proposed modeling and experimental results, a clear path to reach the RON less than 10 electrons is presented.

Original languageEnglish (US)
Article number161101
JournalApplied Physics Letters
Volume114
Issue number16
DOIs
StatePublished - Apr 22 2019

Funding

This work was supported by W. M. Keck Foundation under a Research Grant in Science and Engineering and by partial funding from ARO Award No. W911NF-18-1-0429. This work was performed, in part, at the Center for Nanoscale Materials of Argonne National Laboratory. The use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This work utilized the Northwestern University Micro/Nano Fabrication Facility (NUFAB), which is partially supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the Materials Research Science and Engineering Center (NSF DMR-1720139), the State of Illinois, and Northwestern University.

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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