Enhancing Performance and Uniformity of Perovskite Solar Cells via a Solution-Processed C₇₀ Interlayer for Interface...

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Semiconductor metal oxides (SMOs) are used as electron selective layers (ESLs) in perovskite solar cells (PSCs).
• Limitations of SMO ESLs include low electron mobility and defect formation during low-temperature fabrication, hindering electron transfer.

Purpose of the Study:

• To introduce a C70 interlayer between TiO2 and perovskite in planar n-i-p PSCs.
• To improve electron extraction and perovskite film quality using a low-temperature solution process.

Main Methods:

• Fabrication of a TiO2/C70 electron selective layer via spin-coating and low-temperature annealing.
• Integration of the C70 interlayer between TiO2 and the perovskite absorber layer ((HC(NH2)2PbI3)x(CH3NH3PbCl3)1-x).

Main Results:

• The TiO2/C70 ESL exhibited improved surface morphology and efficient electron extraction.
• The C70 interlayer facilitated the formation of high-quality perovskite films.
• Efficiency was enhanced by 28% and hysteresis index reduced by 76% compared to devices without C70.

Conclusions:

• The C70 interlayer effectively addresses limitations of traditional SMO ESLs in PSCs.
• The low-temperature process and optimized interface offer a viable route for high-performance PSCs.
• Champion efficiencies exceeding 18% on rigid and 12% on flexible substrates were achieved.