POS5-0856
Polymerized Small-Molecule Acceptors with Electron-Withdrawing Substituents Enabling Efficient Charge Transport and Passivation for Inverted Perovskite Solar Cells
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Seungjun Lee (KAIST)
Co-Author(s)
Abstract
Fullerene-based electron transport layers (ETLs) enable high performance in inverted perovskite solar cells (PVSCs) but restrict device efficiency and long-term stability due to limited energy-level tunability, strong aggregation, and insufficient defect passivation.
Here, we report high-performance and photostable inverted PVSCs employing linker-engineered polymerized small-molecule acceptors (PSMAs) as fullerene-free ETLs. A series of structural variants of PSMAs were synthesized by polymerizing Y-based cores with conjugated linkers modified with electron-withdrawing substituents. The introduction of these electron-withdrawing functional groups lowers the energy levels, increases molecular dipole moments, and accelerates electron mobility via enhanced face-on molecular packing. Furthermore, the functional groups effectively passivate perovskite surface defects, facilitating charge extraction and suppressing recombination. Consequently, the optimized PSMA derivative exhibits the highest electron mobility and superior interface passivation. Devices incorporating this functionalized ETL achieve a champion power conversion efficiency exceeding 24% while retaining excellent long-term operational stability under continuous light exposure.
These findings demonstrate that substituent-functionalized PSMAs serve as a powerful fullerene-free ETL to simultaneously achieve high efficiency, defect passivation, and long-term photostability in inverted PVSCs.
Here, we report high-performance and photostable inverted PVSCs employing linker-engineered polymerized small-molecule acceptors (PSMAs) as fullerene-free ETLs. A series of structural variants of PSMAs were synthesized by polymerizing Y-based cores with conjugated linkers modified with electron-withdrawing substituents. The introduction of these electron-withdrawing functional groups lowers the energy levels, increases molecular dipole moments, and accelerates electron mobility via enhanced face-on molecular packing. Furthermore, the functional groups effectively passivate perovskite surface defects, facilitating charge extraction and suppressing recombination. Consequently, the optimized PSMA derivative exhibits the highest electron mobility and superior interface passivation. Devices incorporating this functionalized ETL achieve a champion power conversion efficiency exceeding 24% while retaining excellent long-term operational stability under continuous light exposure.
These findings demonstrate that substituent-functionalized PSMAs serve as a powerful fullerene-free ETL to simultaneously achieve high efficiency, defect passivation, and long-term photostability in inverted PVSCs.
