Goethite Quantum Dots as Multifunctional Additives for Highly Efficient and Stable Perovskite Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Nanotechnology

Background:

• Minimizing defects and ion migration in perovskite films is crucial for efficient and stable photovoltaic devices.
• Developing multifunctional passivators remains a challenge for improving perovskite solar cells (PSCs).

Purpose of the Study:

• To introduce n-type goethite (FeOOH) quantum dots (QDs) as a passivation strategy in perovskite light-absorption layers.
• To enhance the efficiency and long-term stability of perovskite solar cells (PSCs).

Main Methods:

• Incorporation of n-type goethite (FeOOH) quantum dots (QDs) into the perovskite light-absorption layer.
• Analysis of the interactions between FeOOH QDs and perovskite components (iodine, lead, methylamine).
• Characterization of perovskite film quality, trap state passivation, and device performance.

Main Results:

• FeOOH QDs retarded perovskite crystallization, yielding large-grain, high-quality films.
• Effective passivation of trap states by FeOOH QDs through interaction with under-coordinated Pb cations and I anions.
• PSCs with FeOOH QDs achieved near 20% power conversion efficiency (PCE) with negligible hysteresis.
• Significantly enhanced long-term stability of the PSCs.
• A higher PCE of 21.0% was achieved using a mixed perovskite composition (Cs$_{0.05}$ FA$_{0.81}$ MA$_{0.14}$ PbBr$_{0.45}$ I$_{2.55}$) with FeOOH QDs.

Conclusions:

• n-type goethite (FeOOH) quantum dots serve as efficient multifunctional passivators for perovskite solar cells.
• The incorporation of FeOOH QDs leads to improved perovskite film quality, reduced defects, and enhanced device performance and stability.
• This strategy offers a promising pathway for developing highly efficient and durable perovskite-based photovoltaic technologies.