Mechanically Robust and yet Electrically Conductive C60-SnO₂ Electron Transporting Bilayer in Stable Perovskite Solar...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Inverted-type perovskite solar cells (i-PSCs) offer high power conversion efficiencies (PCEs).
• The C60-SnO2 bilayer is a common electron transport layer (ETL) in i-PSCs.
• The C60-SnO2 interface suffers from poor mechanical stability, limiting device longevity.

Purpose of the Study:

• To develop a surface treatment for C60 to improve the mechanical robustness of the C60-SnO2 ETL.
• To enhance electron transport and charge extraction at the ETL interface.
• To improve the overall efficiency and long-term stability of i-PSCs.

Main Methods:

• Atomic layer deposition (ALD) of SnO2 on ozone-treated C60 surfaces.
• Characterization of interface adhesion using mechanical delamination tests.
• Analysis of surface chemistry and electronic properties using X-ray photoelectron spectroscopy (XPS).

Main Results:

• Ozone treatment reduced SnO2 incubation time and improved growth per cycle (GPC).
• Enhanced interface adhesion between C60 and SnO2 was confirmed.
• Ozone treatment led to a slight increase in PCE (21.5% to 21.9%) and remarkable stability (91.9% retention after 2000 h).

Conclusions:

• Surface modification of C60 with ozone is an effective strategy to enhance the C60-SnO2 ETL.
• The proposed method improves mechanical robustness, electron transport, and device stability in i-PSCs.
• This approach offers a pathway for developing more durable and efficient perovskite solar cells.