Lead-chelating hole-transport layers for efficient and stable perovskite minimodules

The defective bottom interfaces of perovskites and hole-transport layers (HTLs) limit the performance of p-i-n structure perovskite solar cells. We report that the addition of lead chelation molecules into HTLs can strongly interact with lead(II) ion (Pb2+), resulting in a reduced amorphous region in perovskites near HTLs and a passivated perovskite bottom surface. The minimodule with an aperture area of 26.9 square centimeters has a power conversion efficiency (PCE) of 21.8% (stabilized at 21.1%) that is certified by the National Renewable Energy Laboratory (NREL), which corresponds to a minimal small-cell efficiency of 24.6% (stabilized 24.1%) throughout the module area. Small-area cells and large-area minimodules with lead chelation molecules in HTLs had a light soaking stability of 3010 and 2130 hours, respectively, at an efficiency loss of 10% from the initial value under 1-sun illumination and open-circuit voltage conditions.

Automated summary

The incorporation of lead chelation molecules into hole-transport layers (HTLs) improves the bottom interfaces of perovskite solar cells, leading to enhanced performance. The addition of these molecules reduces the amorphous region and passivates the perovskite surface near the HTLs. The resulting minimodule achieves a certified power conversion efficiency (PCE) of 21.8% (stabilized at 21.1%) and a minimal small-cell efficiency of 24.6% (stabilized at 24.1%) throughout the module area.