2023/12/04 by Anuja Singh, Singh, Anuja, Bhaskaran Muralidharan +1
Engineering · Physics and Astronomy · #Advanced Semiconductor Detectors and Materials #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Semiconductor Quantum Structures and Devices
paper · pdf · doi:10.48550/arxiv.2312.01604
openalex publication_date 2023/12/04 · openalex created_date 2023/12/06 · openalex updated_date 2026/07/28
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.