Title:	Assessing the Effectiveness of Encapsulation Schemes for Perovskite Devices Using Photoluminescence Imaging
Author(s):	G. Koutsourakis, S.M.P. Meroni, J.C. Blakesley, R. Dix-Peek, R. Dixon, E. van Dyk, P. Obene, I. Arnold, T. Tvapanyan, J. Crozier McCleland, R. Roodt, F. Vorster, A.G.R. Howe, T.M. Watson, F. Araujo de Castro
Keywords:	Photoluminescence, Reliability, Perovskite, Characterisation
Topic:	Evolving and Emerging Technologies: Tandems; Thin Film absorbers; III-V; New Materials and Concepts; Advanced Modelling
Subtopic:	Advanced Modeling and Characterization
Event:	8th World Conference on Photovoltaic Energy Conversion
Session:	2BV.2.39
Pages:	431 - 434
ISBN:	3-936338-86-8
Paper DOI:	10.4229/WCPEC-82022-2BV.2.39
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Photovoltaic (PV) devices based on metal halide perovskite technology are typically more sensitive to environmental conditions, such as moisture and oxygen, than conventional inorganic PV materials like silicon. This means scalability and commercialization of perovskite PV technology are reliant upon highly effective and reliable encapsulation schemes. Evaluation of edge seal materials and encapsulation effectiveness can be challenging, especially if contactless schemes for characterisation are required. In this work, a contactless technique to evaluate encapsulation methods for perovskite devices is presented, based on photoluminescence (PL) imaging. Perovskite devices exhibit a strong PL emission signal when illuminated, while there are dramatic changes in the local PL emission when the devices degrade due to interactions with moisture or oxygen. Such changes in PL signal present an effective way to monitor the effectiveness of encapsulation schemes for perovskite devices. Triple-mesoscopic carbon perovskite mini modules were encapsulated with different schemes and subjected to damp heat aging tests at 85 °C/85 % relative humidity in the dark. PL imaging was used at different times during ageing to monitor the spatial PL emission of samples. In addition, encapsulated devices were placed outdoors and were monitored by PL imaging at frequent intervals in order to compare outdoor exposure with accelerated tests. It has been demonstrated that encapsulation failure can be identified at different times during ageing, with an observed decrease in measured short circuit current of the aged device. Novel encapsulation schemes can be tested using this methodology and compared with more common encapsulation methods.