Electron injection and scaffold effects in perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) show high efficiency, but electron injection and scaffold layer functions remain unclear.
• Understanding these processes is crucial for optimizing PSC performance.

Purpose of the Study:

• To systematically characterize electron injection and scaffold effects in PSCs.
• To investigate the impact of complex mesoporous scaffolds on PSC working principles.

Main Methods:

• Sequential deposition of TiO2 and SiO2 mesoporous layers onto substrates to create complex scaffolds.
• Utilizing impedance spectroscopy to analyze electron injection and interfacial effects.
• Forcing multiple electron injection processes at controlled perovskite-TiO2 interfaces.

Main Results:

• Observed anomalous electron injection behavior, indicated by inductive loops in impedance spectra.
• The magnitude of inductive loops correlated with the number of interfaces in the scaffold.
• Scaffolds were found to hinder ion migration, reducing recombination rates and current-potential hysteresis.

Conclusions:

• Complex scaffolds introduce anomalous injection behavior but can offer benefits by reducing recombination and hysteresis.
• Optimizing PSC performance requires balancing scaffold-induced advantages with charge transport losses.