Planned intervention: On Thursday March 28th 07:00 UTC Zenodo will be unavailable for up to 5 minutes to perform a database upgrade.
Published May 27, 2019 | Version v1
Journal article Open

Controlling competing photochemical reactions stabilizes perovskite solar cells

Description

Metal halide perovskites have become a popular material system for fabricating photovoltaics and various optoelectronic devices. However, long-term reliability must be assured. Instabilities are manifested as light-induced ion migration and segregation, which can lead to material degradation. Discordant reports have shown a beneficial role of ion migration under illumination, leading to defect healing. By combining ab initio simulations with photoluminescence measurements under controlled conditions, we demonstrate that photo-instabilities are related to light-induced formation and annihilation of defects acting as carrier trap states. We show that these phenomena coexist and compete. In particular, long-living carrier traps related to halide defects trigger photoinduced material transformations, driving both processes. Defect formation can be controlled by blocking under-coordinated surface sites, which act as a defect reservoir. By use of a passivation strategy we are thus able to stabilize the perovskite layer, leading to improved optoelectronic material quality and enhanced photostability in solar cells.

Files

23-2019, NatPh, Controlling competing photochemical reactions stabilizes perovskite solar cells.pdf

Additional details

Funding

FASTEST – Fully Air-Processable and Air-Stable Perovskite Solar Cells Based on Inorganic Metal Halide Perovskite Nanocrystals 797546
European Commission
PERTPV – Perovskite Thin-film Photovoltaics (PERTPV) 763977
European Commission
SOPHY – The role of Softness in the Physics of Defects: Probing Buried Interfaces in Perovskites Optoelectronic Devices 771528
European Commission