Surface Chelation Enabled by Polymer-Doping for Self-Healable Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) offer high efficiency but suffer from degradation.
• Achieving efficient self-healing in PSCs under moderate conditions remains a significant challenge.
• Polymer doping is a promising strategy to enhance PSC stability and functionality.

Purpose of the Study:

• To design and introduce a novel self-healable polysiloxane (PAT) into perovskite films for enhanced self-healing properties.
• To investigate the impact of PAT doping on the efficiency, hysteresis, and long-term stability of PSCs.
• To demonstrate the in situ self-healing capabilities of the doped PSCs after mechanical strain.

Main Methods:

• Synthesis of a self-healable polysiloxane (PAT) incorporating abundant thiourea hydrogen bonds.
• Incorporation of PAT into perovskite films to create doped self-healing perovskite solar cells (SHPSCs).
• Characterization of SHPSCs' efficiency, hysteresis, and stability through various testing cycles, including mechanical stretching and in situ observation.

Main Results:

• The doped SHPSCs achieved a champion power conversion efficiency of 19.58% with minimal hysteresis.
• PAT doping effectively facilitated the self-healing of cracks at grain boundaries in the perovskite films.
• After 800 cycles of stretching, releasing, and self-healing, the SHPSCs retained 85% of their initial IPCE, demonstrating remarkable durability.

Conclusions:

• The developed PAT, with its abundant thiourea hydrogen bonds, significantly improves the self-healing efficiency of PSCs.
• This pyridine-based supramolecular doping strategy offers a viable pathway for creating efficient and robust self-healable crystalline semiconductors.
• The findings pave the way for more stable and long-lasting perovskite solar cell technologies.