Stabilizing Efficient Perovskite/Silicon Tandem Solar Cells With Amorphous and Asymmetric Hole-Selective Contacts

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite/silicon tandem solar cells (TSCs) are promising for next-generation photovoltaics.
• Commercialization is hindered by issues with hole-selective contacts, including uneven coverage and thermal instability.

Purpose of the Study:

• To introduce ZF6, a new amorphous molecular contact designed to overcome the limitations of current hole-selective contacts in TSCs.
• To evaluate the performance and stability of TSCs utilizing ZF6.

Main Methods:

• Synthesized and characterized ZF6, an amorphous molecular contact with an asymmetric π-extended structure.
• Fabricated double-junction perovskite/silicon TSCs and triple-junction perovskite/perovskite/silicon TSCs using ZF6.
• Tested device efficiency (power conversion efficiency - PCE) and operational stability under various conditions.

Main Results:

• ZF6 demonstrated rapid, robust adsorption leading to uniform coverage and exceptional thermal stability.
• ZF6-based double-junction TSCs achieved a PCE of 34.02% (certified 32.81%) with high operational stability.
• Triple-junction TSCs achieved a certified PCE of 30.42%, the highest reported for perovskite-based triple-junction TSCs.

Conclusions:

• ZF6 offers a novel design strategy for robust molecular contacts in photovoltaics.
• The developed contact advances the efficiency and durability of perovskite-based tandem solar cells.