Impact Of Temperature And Gamma Radiation On Electron Diffusion Length And Mobility In P-Type Inas/Gasb Superlattices

Abstract

The minority carrier diffusion length was directly measured by the variable-temperature Electron Beam-Induced Current technique in InAs/GaSb type-II strain-layer-superlattice infrared-detector structures. The Molecular Beam Epitaxy-grown midwave infrared superlattices comprised 10 monolayers of InAs and 10 monolayers of GaSb to give a total absorber thickness of 4 μm. The diffusion length of minority electrons in the p-type absorber region of the p-type/barrier/n-type structure was found to increase from 1.08 to 2.24 μm with a thermal activation energy of 13.1 meV for temperatures ranging from 77 to 273 K. These lengths significantly exceed the individual 10-monolayer thicknesses of the InAs and GaSb, possibly indicating a low impact of interface scattering on the minority carrier diffusion length. The corresponding minority electron mobility varied from 48 to 65 cm2/V s. An absorbed gamma irradiation dose of 500 Gy halved the minority carrier diffusion length and increased the thermal activation energy to 18.6 meV, due to creation of radiation-induced defect recombination centers.

Publication Date

6-21-2018

Publication Title

Journal of Applied Physics

Volume

123

Issue

23

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1063/1.5030444

Socpus ID

85048772292 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85048772292

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