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Main Authors: Singh, Anuja, Muralidharan, Bhaskaran
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2312.01604
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author Singh, Anuja
Muralidharan, Bhaskaran
author_facet Singh, Anuja
Muralidharan, Bhaskaran
contents A holistic computational analysis is developed to calculate the quantum efficiency of InAs/GaSb superlattice-based photodetectors. Starting with the electronic band characteristics computed by taking the InSb/GaAs at the interface using the 8-band k.p approach, we demonstrate the impact of InAs and GaSb widths on the bandgap, carrier concentration, and the oscillator strength for type-II superlattice absorbers. Subsequently, the alteration of these characteristics due to the extra AlSb layer in the M superlattice absorber is investigated. Extending our models for determining TE- and TM-polarized optical absorption, our calculations reveal that the TE-polarized absorption shows a substantial influence near the conduction-heavy hole band transition energy, which eventually diminishes, owing to the dominant TM-contribution due to the conduction-light hole band transition. Extending our analysis to the dark currents, we focus mainly on Schokley-Read-Hall recombination and radiative recombination at lower temperatures, and show that Schokley-Read-Hall dominates at low-level injection. We show that short-wavelength and mid-wavelength M superlattice structures exhibit higher quantum efficiency than the corresponding same bandgap type-II superlattice with the lower diffusion dark current. Further, we analyze the density of states blocked by the barrier; crucial for XBp photodetector after absorber examination. Our work thus sets a stage for a holistic and predictive theory aided analysis of the type-II superlattice absorbers, from the atomistic interfacial details all the way to the dark currents and absorption spectra.
format Preprint
id arxiv_https___arxiv_org_abs_2312_01604
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Insights into optical absorption and dark currents of the 6.1Å Type-II superlattice absorbers for MWIR and SWIR applications
Singh, Anuja
Muralidharan, Bhaskaran
Mesoscale and Nanoscale Physics
Materials Science
A holistic computational analysis is developed to calculate the quantum efficiency of InAs/GaSb superlattice-based photodetectors. Starting with the electronic band characteristics computed by taking the InSb/GaAs at the interface using the 8-band k.p approach, we demonstrate the impact of InAs and GaSb widths on the bandgap, carrier concentration, and the oscillator strength for type-II superlattice absorbers. Subsequently, the alteration of these characteristics due to the extra AlSb layer in the M superlattice absorber is investigated. Extending our models for determining TE- and TM-polarized optical absorption, our calculations reveal that the TE-polarized absorption shows a substantial influence near the conduction-heavy hole band transition energy, which eventually diminishes, owing to the dominant TM-contribution due to the conduction-light hole band transition. Extending our analysis to the dark currents, we focus mainly on Schokley-Read-Hall recombination and radiative recombination at lower temperatures, and show that Schokley-Read-Hall dominates at low-level injection. We show that short-wavelength and mid-wavelength M superlattice structures exhibit higher quantum efficiency than the corresponding same bandgap type-II superlattice with the lower diffusion dark current. Further, we analyze the density of states blocked by the barrier; crucial for XBp photodetector after absorber examination. Our work thus sets a stage for a holistic and predictive theory aided analysis of the type-II superlattice absorbers, from the atomistic interfacial details all the way to the dark currents and absorption spectra.
title Insights into optical absorption and dark currents of the 6.1Å Type-II superlattice absorbers for MWIR and SWIR applications
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2312.01604