Interface-oriented bridges toward efficient carbon-based perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• The interface between perovskite and electron transport layers is crucial for perovskite solar cell (PSC) performance and stability.
• Defects and poor energy level alignment at this interface limit device efficiency and operational lifetime.

Purpose of the Study:

• To investigate potassium bisaccharate (PB) as a multifunctional interfacial modifier for the electron transport layer/perovskite layer in PSCs.
• To enhance the efficiency and long-term stability of carbon-based PSCs through buried interface engineering.

Main Methods:

• Introduction of potassium bisaccharate (PB) into the buried interface between the SnO2 electron transport layer and the perovskite layer.
• Characterization using sum-frequency generation (SFG) spectroscopy to confirm molecular orientation and energy level alignment.
• Fabrication and testing of carbon-based PSCs with PB-modified interfaces.

Main Results:

• PB acts as a chemical bridge, anchoring to the SnO2 surface via covalent interactions and passivating under-coordinated Pb2+ defects in the perovskite.
• SFG spectra confirmed the out-of-plane orientation of PB and optimized energy level alignment.
• PB-treated carbon-based PSCs achieved a champion power conversion efficiency (PCE) of 19.69% and maintained 95.8% of their initial efficiency after 1200 hours under ambient conditions.

Conclusions:

• Potassium bisaccharate (PB) effectively modifies the buried interface in PSCs, improving both power conversion efficiency and operational stability.
• PB demonstrates significant potential as a buried interface modifier for advancing carbon-based PSC technology.