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2022 PVSC-Effect of Dilute Acid Exposure on Sol-gel porous silica AR coatings.pdf (281.11 kB)
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Effect of dilute acid exposure on sol-gel porous silica anti-reflection coatings

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conference contribution
posted on 2023-01-06, 10:27 authored by Farwah BukhariFarwah Bukhari, Luke JonesLuke Jones, Adam Law, Ali AbbasAli Abbas, Michael WallsMichael Walls
The build-up of algae and moss on the outer glass surface of solar modules causes serious attenuation of the incident light. Biocides are effective in removing this surface contamination to restore performance. These biocides are acid based and there is some concern that their use may affect the integrity of the porous silica anti-reflection coatings (ARC). Here we report on the effect of a commercial biocide treatment on sol-gel porous silica AR coatings. The biocide used was SFC Eco which is already deployed on solar utilities. Our initial studies show the effectiveness of nonanoic acid-based biocide as an algae cleaning solution. The treatment using a dilute solution does slightly etch the morphology of the coating. Similar effects could also be caused by acids in rainfall, so we have also conducted tests using sulphuric, nitric and carbonic acids at similar dilutions. These tests showed that these tests also resulted in similar etching but that there no significant change in the transmittance or reflectance of the coating. Our studies are continuing to investigate if long term exposure to acidic environment or cyclic applications of biocides will cause significant degradation.


A durable and scalable anti-soiling coating for solar modules

Engineering and Physical Sciences Research Council

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  • Mechanical, Electrical and Manufacturing Engineering

Research Unit

  • Centre for Renewable Energy Systems Technology (CREST)

Published in

2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)


705 - 707


2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)


Institute of Electrical and Electronics Engineers (IEEE)


  • AM (Accepted Manuscript)

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© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

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Philadelphia, PA, USA

Event dates

5th June 2022 - 10th June 2022


Prof Michael Walls. Deposit date: 5 January 2023

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