Influence of Agricultural Environment on the Degradation of CIGS-Based Solar Cells

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Current approaches to reliability in photovoltaics focus mainly on the effects of temperature, illumination, or mechanical load, while among the chemical factors, only humidity is generally considered [1]. In this work, we took into account the presence of ammonium sulfate (NH4)2SO4, an atmospheric pollutant generated by agricultural activities [2], [3]. We sought to understand its impact on the stability of CIGS solar cell materials and interfaces, relevant technology for flexible applications. Our previous research demonstrated that thin Al2O3 encapsulation, efficient in damp heat test [4], was dissolved by (NH4)2 SO4 [5], [6]. The current study therefore presents the tests obtained on non-encapsulated cells and representative stacks of layers. The samples were subjected to accelerated aging tests involving daily variations in humidity and temperature with and without (NH4)2 SO4 deposition. Loss of performance was assessed with IV curves and EQE and chemical modification was evaluated by Raman spectroscopy, SEM-EDX and GD-OES. Unencapsulated samples aged without pollutant lost 37% loss of efficiency in just 9 days. The loss mainly due to a decrease in Voc and Rsh, which could be explained by an increase in recombination in the CIGS and its interfaces. New species, Cu(2-x)Se and NaxMoyOz, which formation was confirmed by in situ Raman, could act as recombination centers or shunt paths. In the presence of (NH4)2 SO4, the reduction in efficiency was 60% after rinsing. The efficiency degradation was mainly due to a loss of Jsc and FF. The current was certainly affected by the transformation of transparent conductive oxide AZO in Zn4(SO4)(OH)6 · nH2O. The FF loss could be linked to an increase in contact resistance, evidenced by Rsheet measurement of Mo and AZO. Raman evidenced the oxidation of Mo and local dissolution of AZO. In conclusion, fertilizers can significantly affect reliability of thin layer solar cells and their presence must be considered for agrivoltaics.

Original languageEnglish
Title of host publication2024 IEEE 52nd Photovoltaic Specialist Conference, PVSC 2024
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages590-592
Number of pages3
ISBN (Electronic)9781665464260
DOIs
Publication statusPublished - 1 Jan 2024
Event52nd IEEE Photovoltaic Specialist Conference, PVSC 2024 - Seattle, United States
Duration: 9 Jun 202414 Jun 2024

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371

Conference

Conference52nd IEEE Photovoltaic Specialist Conference, PVSC 2024
Country/TerritoryUnited States
CitySeattle
Period9/06/2414/06/24

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