Abstract
We report on a planar long-wavelength infrared photodetector based on InAs/InAs1-xSbx type-II superlattice with zinc diffusion. The superlattice structures were grown by molecular beam epitaxy, followed by a post-growth Zinc diffusion process in a metal-organic chemical vapor deposition reactor. The planar photodetectors showed a peak responsivity of 2.18 A/W, under an applied bias of-20 mV, with a corresponding quantum efficiency of 44.5%, without any anti-reflection coating, and had a 100% cut-off wavelength of 8.5 μm at 77 K temperature. These photodetectors exhibit a specific peak detectivity of 3.0 × 1012 cm.Hz1/2/W, with a dark current density of 1.5× 10-5 A/cm2 and the differential-resistance-area product of ∼ 8.6×10-1 Ω .cm2, under an applied bias of-20 mV at 77 K. A comparative study between the planar and conventional mesa-isolated photodetectors was also carried out.
Original language | English (US) |
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Article number | 4000306 |
Journal | IEEE Journal of Quantum Electronics |
Volume | 58 |
Issue number | 5 |
DOIs | |
State | Published - Oct 1 2022 |
Funding
This work was supported by the CQD/Northwestern University through Walter P. Murphy society.
Keywords
- Planar photodetector
- Zinc diffusion
- long-wavelength infrared
- molecular beam epitaxy
- type II superlattice
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering