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Significant suppression of surface leakage in GaSb/AlAsSb heterostructure with Al2O3 passivation

Chen, Andrew, Juang, Bor-Chau, Ren, Dingkun, Liang, Baolai, Prout, David L., Chatziioannou, Arion F. and Huffaker, Diana L. ORCID: 2019. Significant suppression of surface leakage in GaSb/AlAsSb heterostructure with Al2O3 passivation. Japanese Journal of Applied Physics 58 (9) , 090907. 10.7567/1347-4065/ab3909

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This work develops a (NH4)2S/Al2O3 passivation technique for photodiode-based GaSb/AlAsSb heterostructure. Surface-sulfurated GaSb/AlAsSb heterostructure mesas show a significant suppression of reversed-bias dark current by 4–5 orders of magnitude after they are further passivated by Al2O3 layers. So the mesa sidewalls treated with (NH4)2S/Al2O3 layers can effectively inhibit the shunt path of dark carriers. The activation energies for both bulk and surface components are extracted from temperature-dependent current–voltage characteristics, which suggest that the bulk characteristics remain unchanged, while Fermi-level pinning at surfaces is alleviated. Additionally, temperature coefficients of the breakdown voltage are extracted, confirming that the breakdown process is confined entirely in the large bandgap AlAsSb regions. This study shows that the implementation of (NH4)2S/Al2O3 passivation can lead to room temperature GaSb-based photodiodes and GaSb/AlAsSb-based avalanche photodiodes for highly efficient photodetection.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Publisher: Japan Society of Applied Physics
ISSN: 0021-4922
Date of First Compliant Deposit: 31 October 2019
Date of Acceptance: 5 August 2019
Last Modified: 13 Nov 2023 05:36

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