Outgassing

Electrical engineering

Engineering

Perovskite (structure)

Nanotechnology

Organic chemistry

Chemistry

Materials science

Energy conversion efficiency

Degradation (telecommunications)

Photovoltaic system

Chemical engineering

Optoelectronics

Joule

High specific power, high stowed packing efficiency, low processing cost, and high tolerance against environmental threats (high energy and charged particle radiation) make perovskite solar cell (PSC) a promising candidate for power generation in space. However, vacuum, as encountered in space, causes perovskite outgassing, raising concern for its long-term stability. In this work, we find that PSCs (ITO/SnO2/perovskite/Spiro-MeOTAD/Au) degrade ten times faster upon reducing the pressure from 9 × 104 to 5 × 103 Pa during operation, due to acceleration of the perovskite transformation and ion migration. Gas permeability of the layers atop perovskite and mobile ion-induced chemical reactions at charge transporting layers and related interfaces are two critical factors. We develop a PSC structure (ITO/PTAA/perovskite/PCBM/ZnO/AZO/[Ni/Al grid]) that effectively mitigates vacuum and illumination-induced degradation pathways, enabling PSCs to realize a low PCE loss rate of 0.007%/h over 1,037 h at the maximum power point under 100 mW cm−2 illumination at 5 × 103 Pa.

Mitigation of Vacuum and Illumination-Induced Degradation in Perovskite Solar Cells by Structure Engineering