Efficient Perovskite Solar Cells with Enhanced Thermal Stability by Sulfide Treatment

Abstract

The performance degradation of perovskite solar cells (PSCs) under harsh environment (e.g., heat, moisture, light) is one of the greatest challenges for their commercialization. Herein, a conjugated sulfide 2-mercaptobenzimidazole (2MBI) is applied to significantly improve the photovoltaic properties and thermal stability of PSCs. When treated with heat, 2MBI cross-links with each other on the perovskite surface to facilitate charge transportation, suppress the escape of volatile species, and guide the rearrangement of surface perovskite grains. PSCs with 2MBI modification reach a PCE as high as 21.7% and maintain high-efficiency output during and after thermodestruction at 85 °C, while the unmodified ones suffer severe degradation. Unencapsulated devices after thermodestruction achieve over 98% of initial efficiency after 40-day storage under ambient conditions.

Improved Air Stability for High-Performance FACsPbI3 Perovskite Solar Cells via Bonding Engineering

“…The ESP map shows that positive charges are distributed around alkyl long chains and negative charges are distributed around thiol groups. Based on previous reports, it can be inferred that the hydrophobic alkyl chains in PT are helpful to improve the overall moisture resistance of the films, while terminal thiol groups can anchor uncoordinated Pb 2+ ions to regulate halide vacancy defects on the grain boundaries/surfaces of perovskite films. – By mixing with CB as antisolvent, PT molecules are introduced into perovskite films and produce a passivation effect, and the detailed preparation process is shown in Figure b. To investigate the surface composition and chemical interactions of perovskite films with and without PT, we performed XPS measurements.…”