Stabilizing Sputtered NiO_x via In Situ Dissociative Adsorption Passivation for Efficient Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Sputtered nickel oxide (NiO_x) is a viable hole transport layer for perovskite solar cells (PSCs).
• Interfacial instability due to disordered Ni³⁺ and perovskite reactions limits NiO_x performance.
• Existing passivation methods struggle to address these interfacial challenges effectively.

Purpose of the Study:

• To develop a novel passivation strategy for sputtered NiO_x in PSCs.
• To enhance the interfacial stability and performance of NiO_x-based PSCs.
• To mitigate degradation pathways and improve the operational lifetime of PSCs.

Main Methods:

• Introduction of an in situ dissociative adsorption passivation (IDAP) strategy using bromoacetamide (BAA).
• Coordination of Br^- ions with surface Ni to block sites and stabilize Ni³⁺.
• Dual anchoring by the amide group (N-H···O hydrogen bonding) and carbonyl group (C═O) for passivation of Pb²⁺.

Main Results:

• Passivation significantly reduced trap states and interfacial redox reactions.
• NiO_x-based PSCs achieved a champion power conversion efficiency (PCE) of 26.31% (certified 26.07%).
• Large-area (1 cm²) PSCs maintained 25.48% efficiency, with 93% performance retention after 1500 hours.

Conclusions:

• The IDAP strategy effectively stabilizes sputtered NiO_x, addressing key interfacial limitations.
• This approach leads to record efficiencies for NiO_x-based PSCs and demonstrates excellent long-term operational stability.
• Bromoacetamide passivation offers a promising pathway for scalable and high-performance perovskite solar cell development.