Improved stability of black silicon detectors using aluminum oxide surface passivation
Loading...
Access rights
openAccess
Journal Title
Journal ISSN
Volume Title
A4 Artikkeli konferenssijulkaisussa
This publication is imported from Aalto University research portal.
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
Date
2021-06-11
Major/Subject
Mcode
Degree programme
Language
en
Pages
7
118520T
118520T
Series
SPIE CONFERENCE PROCEEDINGS, Volume 11852
Abstract
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.Description
Keywords
black silicon, photodiode, irradiation, humidity
Other note
Citation
Heinonen, J, Haarahiltunen, A, Kettunen, H, Jaatinen, J, Rossi, M, Heino, J, Savin, H & Juntunen, M 2021, Improved stability of black silicon detectors using aluminum oxide surface passivation . in International Conference on Space Optics: ICSO 2020 . vol. 11852, SPIE Conference Proceedings, SPIE, pp. 118520T, International Conference on Space Optics, Antiber Juan-le-Pins, France, 19/10/2020 . https://doi.org/10.1117/12.2599177
