Perovskite/silicon tandem solar cells with bilayer interface passivation

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite/silicon tandem solar cells offer higher power conversion efficiencies (PCEs) than single-junction cells.
• A key challenge is minimizing recombination at the perovskite/electron transport layer interface without hindering charge transport.

Purpose of the Study:

• To develop an effective interfacial passivation strategy for perovskite/silicon tandem solar cells.
• To enhance electron extraction and suppress non-radiative recombination.
• To achieve high PCEs exceeding the Shockley-Queisser limit.

Main Methods:

• Employed a bilayer-intertwined passivation strategy using lithium fluoride ultrathin layers and diammonium diiodide molecules.
• Fabricated tandem devices on a double-textured silicon heterojunction cell (mildly textured front, heavily textured rear).
• Utilized advanced characterization to confirm enhanced photocurrent and passivation.

Main Results:

• Achieved a certified stabilized power conversion efficiency of 33.89%.
• Recorded an impressive fill factor of 83.0% and an open-circuit voltage of nearly 1.97 V.
• Demonstrated simultaneous enhancement of photocurrent and rear surface passivation.

Conclusions:

• The bilayer-intertwined passivation strategy effectively suppresses interfacial recombination and enhances charge extraction.
• The developed perovskite/silicon tandem solar cell achieves a record certified efficiency, surpassing the single-junction Shockley-Queisser limit.
• This work paves the way for next-generation high-efficiency photovoltaic devices.