Interface Optoelectronics Engineering for Mechanically Stacked Tandem Solar Cells Based on Perovskite and Silicon

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Tandem solar cells offer enhanced efficiency by combining different light-absorbing materials.
• Integrating perovskite and silicon solar cells presents challenges in interface engineering and charge transport.

Purpose of the Study:

• To engineer photonics for antireflection and electronics for hole extraction in perovskite/silicon tandem solar cells.
• To optimize a tunneling junction for efficient charge recombination between the top perovskite and bottom silicon cells.

Main Methods:

• Fabrication of mechanically stacked tandem solar cells using CH3NH3PbI3 perovskite and p-type single crystal silicon (c-Si).
• Engineering of a highly transparent connection multilayer (evaporated-Au and sputtered-ITO films) as a point-contact tunneling junction.
• Optimization of the tunneling junction structure: perovskite/Au (2.5 nm)/ITO (154 nm) stacked-on ITO (108 nm)/c-Si.

Main Results:

• Achieved a thin gold layer (2.5 nm) for effective hole extraction and antireflection properties.
• Demonstrated a highly transparent and efficient tunneling junction between the perovskite and silicon sub-cells.
• The optimized tandem solar cell reached a power conversion efficiency of 13.7% for two-terminal and 14.4% for four-terminal configurations.

Conclusions:

• The developed tunneling junction effectively connects perovskite and silicon solar cells, enabling efficient charge transfer.
• This work presents a viable pathway for high-efficiency perovskite/silicon tandem solar cells through optimized interface engineering.