[2PS-119]
Realization of High-Efficiency and Stable Perovskite Solar Cells via Defect Passivation and Gradual Energy Band Tuning
발표자이유민 (dgist)
연구책임자최종민 (digist)
Abstract
Passivation engineering is essential for enhancing the efficiency and stability of perovskite solar cells (PSCs). Grain boundaries (GBs) in perovskite films contain defects that cause non-radiative recombination and allow moisture, oxygen, and lithium ions to penetrate, accelerating degradation. Lewis base-containing polymers can passivate these defects by forming Lewis adducts with uncoordinated Pb²⁺ ions.Conventional polymer passivation faces trade-offs: high concentrations offer full coverage but increase resistance, while low concentrations reduce resistance but leave GBs exposed. To address this, we developed a multifunctional polymer enabling dual passivation in both the perovskite and hole transport layers (HTL). This strategy reduces band offset, blocks lithium-ion migration, and suppresses pinhole and void formation. As a result, our PSCs achieved 24.0% power conversion efficiency and retained 92% of initial performance after 2000 hours in ambient conditions.