A Stepwise Melting-Polymerizing Molecule for Hydrophobic Grain-Scale Encapsulated Perovskite Solar Cell.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face significant stability challenges, hindering commercialization despite efficiency gains.
• Humidity-induced degradation is a primary concern for FAPbI3-based PSCs.

Purpose of the Study:

• To develop a strategy to enhance the stability and commercial viability of FAPbI3 perovskite solar cells.
• To address humidity-induced degradation and improve operational longevity.

Main Methods:

• A stepwise melting-polymerizing molecule (SMPM) was designed as an additive for FAPbI3 perovskite.
• SMPM undergoes melting, grain boundary overflow, and self-polymerization to form a hydrophobic encapsulation during annealing.
• Characterization of perovskite crystallization, recombination, energy levels, and device performance.

Main Results:

• SMPM additive improved crystallization, reduced non-radiative recombination, and aligned energy levels in FAPbI3 PSCs.
• Achieved power conversion efficiencies of 25.21% (small-area) and 22.94% (1 cm2).
• Demonstrated over 2000 hours of T95% stability under 85% relative humidity and remarkable underwater operational stability without external encapsulation.

Conclusions:

• The SMPM strategy effectively mitigates humidity-induced degradation through hydrophobic encapsulation.
• SMPM offers a sustainable solution for enhancing PSC stability and addressing environmental concerns.
• This approach significantly advances the commercialization prospects of perovskite solar cells.