Electrical engineering

Fabrication

Pathology

Nanotechnology

Tandem

Engineering physics

Engineering

Perovskite (structure)

Catalysis

Composite material

Chemistry

Metallurgy

Materials science

Alternative medicine

Layer (electronics)

Oxide

Photovoltaic system

Solar cell

Tin oxide

Passivation

Chemical engineering

Optoelectronics

Biochemistry

Medicine

Mesoporous material

Advanced Materials

Perovskite solar cells (PSCs) have become a promising photovoltaic (PV) technology, where the evolution of the electron‐selective layers (ESLs), an integral part of any PV device, has played a distinctive role to their progress. To date, the mesoporous titanium dioxide (TiO 2 )/compact TiO 2 stack has been among the most used ESLs in state‐of‐the‐art PSCs. However, this material requires high‐temperature sintering and may induce hysteresis under operational conditions, raising concerns about its use toward commercialization. Recently, tin oxide (SnO 2 ) has emerged as an attractive alternative ESL, thanks to its wide bandgap, high optical transmission, high carrier mobility, suitable band alignment with perovskites, and decent chemical stability. Additionally, its low‐temperature processability enables compatibility with temperature‐sensitive substrates, and thus flexible devices and tandem solar cells. Here, the notable developments of SnO 2 as a perovskite‐relevant ESL are reviewed with emphasis placed on the various fabrication methods and interfacial passivation routes toward champion solar cells with high stability. Further, a techno‐economic analysis of SnO 2 materials for large‐scale deployment, together with a processing‐toxicology assessment, is presented. Finally, a perspective on how SnO 2 materials can be instrumental in successful large‐scale module and perovskite‐based tandem solar cell manufacturing is provided.

Tin Oxide Electron‐Selective Layers for Efficient, Stable, and Scalable Perovskite Solar Cells