MXene-Regulated Perovskite Vertical Growth for High-Performance Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Interface defects in perovskite (PVK) thin films significantly reduce the photoelectric conversion efficiency (PCE) and stability of perovskite solar cells (PSCs).
• Effective passivation of the electron transport layer (ETL)/perovskite interface is crucial for developing high-performance and durable PSCs.

Purpose of the Study:

• To develop a SnO2-MXene composite ETL for PSCs to improve interfacial contact and passivate defects.
• To investigate the effect of the MXene component on SnO2 dispersion and perovskite film growth.
• To enhance the PCE and long-term stability of PSCs.

Main Methods:

• Fabrication of PSCs utilizing a SnO2-MXene composite ETL.
• Characterization of the SnO2/perovskite interface and perovskite film morphology.
• Performance testing of the fabricated solar cells, including PCE and short-circuit current measurements.
• Stability testing under ambient conditions (humidity and air exposure).

Main Results:

• The SnO2-MXene composite ETL effectively passivated defects at the SnO2/perovskite interface.
• MXene addition regulated SnO2 dispersion and promoted vertical perovskite growth, leading to reduced interfacial stress and fewer defects.
• The SnO2-MXene based PSCs exhibited a 15% PCE improvement compared to SnO2-based devices, with a short-circuit current of 25.07 mA cm⁻².
• Unencapsulated devices maintained 90% of their initial efficiency after 500 hours of storage under ambient conditions.

Conclusions:

• The SnO2-MXene composite ETL is a promising strategy for interfacial engineering in PSCs.
• This approach enhances both the efficiency and operational stability of perovskite solar cells.
• The findings offer a new route for defect passivation in metal halide perovskite-based devices.