Mimicking Outdoor Ion Migration in Perovskite Solar Cells - A Forward Bias, NoLight Accelerated Aging Approach

Sep 21, 2026

Uploaded by Theodora

Perovskite solar cells require urgent stability assessment because their operational durability is not yet fully proven, especially under accelerated aging. The study introduces a dark-only accelerated aging procedure: prolonged forward biasing followed by a dark postbias rest. Forward bias triggers ion migration, causing impaired charge transport, macroscopic defect growth, and worse response to brief light soaking; recovery occurs during postbias rest, yet increased recombination persists due to ion redistribution. Outdoor data from Berlin over 20 months show aligned dynamics with these phases, enabling illumination-free outdoor-mimicking aging tests.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

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Abstract

Accelerated aging procedure without illumination

Ion migration effects during forward bias

Postbias rest recovery and residual recombination

Outdoor validation in Berlin and phase alignment

Background: stability limits and ISOS protocols

Mobile ion migration and electric-field-driven degradation

ISOSV-1 and prior bias-induced degradation findings

This article is licensed under CC-BY 4.0 | [http://pubs.acs.org/journal/aelccp](http://pubs.acs.org/journal/aelccp)
Mimicking Outdoor Ion Migration in Perovskite Solar Cells: A Forward Bias, NoLight Accelerated Aging Approach
Ulas Erdil, Mark Khenkin, * Marko Remec, Quiterie Emery, Vediappan Sudhakar, Rutger Schlatmann, Antonio Abate, Eugene A. Katz, and Carolin Ulbrich
Cite This: ACS Energy Lett. 2025, 10, 1529−1537

Read Online | | | | | | | --- | --- | --- | --- | --- | --- | | ACCESS | Metrics & More | | Article Recommendations | | *sı Supporting Information | ABSTRACT: Perovskite solar cells (PSCs) are expected to transform the photovoltaic market; however, their unproven operational stability requires urgent attention, particularly accelerated aging tests. Currently, illumination is the primary stressor in such tests. In this work, we present an accelerated aging procedure consisting of prolonged forward biasing followed by a dark storage (postbias rest) phase, conducted entirely in the dark. During aging under forward bias, ion migration led to impeded charge transport, macroscopic defect growth, and an adverse response of the cells to short light soaking, all of which recovered in the postbias rest phase, yet resulted in increased recombination due to redistribution of ions. We found that outdoor operation of PSCs in Berlin, Germany, over a 20-month period exhibited similar dynamics, with periods of higher temperature and irradiance (spring-summer) aligning with the forward bias phase and cooler, dimmer periods (fall−winter) aligning with the postbias rest phase. This paves the way for accelerated aging tests that can mimic ion migration-induced degradation outdoors without requiring an illumination source. Although perovskite-based solar cells (PSCs) achieved high efficiency1 and promise a low levelized cost of electricity,2 the long-term stability of PSCs is still behind that of commercial silicon-based photovoltaic technologies.3 Conducting accelerated aging tests, where PSCs are exposed to higher stress levels than encountered at real operation conditions, is a common practice to quickly investigate stability with the ultimate goal of lifetime prediction.4 This is inevitable because investigating degradation under real operation conditions requires a significant amount of time as the technology matures, reaching an estimated lifetime of tens of thousands of hours.5 However, outdoor tests remain mandatory to validate that the degradation mechanisms and trends simulated via accelerated aging tests are relevant to real operation conditions.6 In this direction, the International Summit on Organic Photovoltaic Stability (ISOS) protocols define the frameworks of both indoor and outdoor stability tests of PSCs.7 PSCs are susceptible to various stressors and can experience multiple degradation mechanisms,8,9 sometimes dominated by a single mechanism10 or involving several competing ones.11 Perhaps the most common origin for a variety of degradation mechanisms in PSCs is the migration of mobile ions, an intrinsic phenomenon in perovskite absorber.12 The soft perovskite structure, combined with its low defect formation energy, readily facilitates ion migration when subjected to stressors 13 such as illumination, 14−16 temperature, 17 and external bias.18, 19 Given that PSCs will operate at maximum power point (MPP), which corresponds to a forward bias, during outdoor operation,7 mobile ions will experience an electric field that drives their migration.20 One straightforward way to simulate this bias condition and investigate ion migration-induced degradation is to apply continuous forward bias (positive voltage) in the dark, also referred to as the ISOSV-1 protocol.7 In this direction, Bae and colleagues found that PSCs undergo rapid degradation due to ion migration when the applied voltage is higher than the built-in voltage or opencircuit voltage (VOC).21 Later, Di Girolamo et

FAQs

What aging procedure does the paper propose to mimic outdoor conditions?

It applies prolonged forward bias in complete darkness, then follows with a dark postbias rest (postbias rest) phase.

What degradation mechanisms occur during forward bias under dark conditions?

Ion migration impedes charge transport, increases macroscopic defect growth, and leads to an adverse response after short light soaking.

How does the postbias rest phase affect the cells and what issue remains?

The cells recover during postbias rest, but increased recombination remains due to redistribution of ions.

Sep 21, 2026

Uploaded by Theodora