A4 Article in conference proceedings
Improved stability of black silicon detectors using aluminum oxide surface passivation (2021)

Heinonen, J., Haarahiltunen, A., Kettunen, H., Jaatinen, J., Rossi, M., Heino, J., Savin, H., & Juntunen, M. A. (2021). Improved stability of black silicon detectors using aluminum oxide surface passivation. In Z. Sodnik, B. Cugny, & N. Karafolas (Eds.), International Conference on Space Optics : ICSO 2020 (Article 118520T-2). SPIE. Proceedings of SPIE : the International Society for Optical Engineering, 11852. https://doi.org/10.1117/12.2599177

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Publication details

All authors or editors: Heinonen, Juha; Haarahiltunen, Antti; Kettunen, Heikki; Jaatinen, Jukka; Rossi, Mikko; Heino, Jouni; Savin, Hele; Juntunen, Mikko A.

Parent publication: International Conference on Space Optics : ICSO 2020

Parent publication editors: Sodnik, Zoran; Cugny, Bruno; Karafolas, Nikos


  • International Conference on Space Optics

Place and date of conference: Online, 30.3-2.4.2021

ISBN: 978-1-5106-4548-6

eISBN: 978-1-5106-4549-3

Journal or series: Proceedings of SPIE : the International Society for Optical Engineering

ISSN: 0277-786X

eISSN: 1996-756X

Publication year: 2021

Publication date: 11/06/2021

Number in series: 11852

Article number: 118520T-2

Publisher: SPIE

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1117/12.2599177

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/77061


We have studied how high-energy electron irradiation (12 MeV, total dose 66 krad(Si)) and long term humidity exposure (75%, 75 ˚C, 500 hours) influence the induced junction black silicon or planar photodiode characteristics. In our case, the induced junction is formed using n-type silicon and atomic-layer deposited aluminum oxide (Al2O3), which contains a large negative fixed charge. We compare the results with corresponding planar pn-junction detectors passivated with either with silicon dioxide (SiO2) or Al2O3. The results show that the induced junction detectors remain stable as their responsivity remains nearly unaffected during the electron beam irradiation. On the other hand, the SiO2 passivated counterparts that included conventional pn-junction degrade heavily, which is seen as strongly reduced UV response. Similarly, after humidity test the response of the induced junction detector remains unaffected, while the pn-junction detectors passivated with SiO2 degrade significantly, for instance, the response at 200 nm reduces to 50% from the original value. Interestingly, the pn-junction detectors passivated with Al2O3 exhibit no degradation of UV response, indicating that the surface passivation properties of Al2O3 are more stable than SiO2 under the studied conditions. This phenomenon is further confirmed with PC1D simulations suggesting that the UV degradation results from increased surface recombination velocity. To conclude, the results presented here suggest that black silicon photodiodes containing Al2O3-based induced junction are highly promising alternatives for applications that require the best performance and long-term stability under ionizing and humid conditions.

Keywords: radiation physics; electronic components; detectors; semiconductors; silicon dioxide; aluminum oxide; ionising radiation; air humidity

Free keywords: black silicon; photodiode

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Ministry reporting: Yes

Reporting Year: 2021

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Last updated on 2022-20-09 at 13:20