Dynamic self-regulating interfaces enable crystallization control and lead sequestration in perovskite photovoltaics

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Carbon-electrode, hole-transport-layer-free perovskite solar cells (C-PSCs) show commercial promise but face challenges with uncontrolled crystallization and film defects.
• Existing interfacial modifications lack kinetic control over crystallization, hindering performance and leading to non-radiative losses.

Purpose of the Study:

• To develop a dynamic, self-regulating interface strategy for C-PSCs using nickel acetate (NA).
• To kinetically regulate crystallization and passivate interfacial defects for improved perovskite solar cell performance and stability.

Main Methods:

• Utilized nickel acetate (NA) for in situ generation of a Pb²⁺ complex reservoir via reversible ion exchange.
• Employed the controlled release of Pb²⁺ to suppress nucleation and passivate defects.
• Optimized energy-level alignment for enhanced charge extraction.

Main Results:

• Achieved a record power conversion efficiency (PCE) of 18.43% in NA-modified C-PSCs, compared to 14.11% for the control.
• Demonstrated exceptional operational stability due to reduced non-radiative losses.
• Significantly reduced lead leakage through a dual-function mechanism involving chemical bonding and a physical barrier.

Conclusions:

• The dynamic interface strategy using NA effectively controls crystallization and passivates defects, leading to highly efficient C-PSCs.
• The developed method establishes a dual-function paradigm for stable and eco-compatible perovskite photovoltaics.
• This approach offers a pathway towards commercializing perovskite solar technology with enhanced safety and performance.