Polymer-modified halide perovskite films for efficient and stable planar heterojunction solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Solution-processed perovskite films often have trap states that hinder optoelectronic performance.
• Small-molecule surfactants have been used to enhance perovskite properties.

Purpose of the Study:

• To investigate the use of polymers with coordinating groups as modifiers for solution-processed semiconductor films.
• To improve the performance and stability of perovskite solar cells using polymer additives.

Main Methods:

• Demonstrated the use of poly(4-vinylpyridine) (PVP) as a polymer modifier for perovskite films.
• Measured carrier dynamics and device performance to evaluate the electronic properties of the modified films.
• Assessed power conversion efficiency, open-circuit voltage (V_OC), and shelf-life stability of the perovskite solar cells.

Main Results:

• PVP treatment significantly enhanced power conversion efficiency from 16.9% to 18.8% (champion 20.2%) and stabilized efficiency to 19.1%.
• Achieved a high open-circuit voltage (V_OC) of up to 1.16 V, indicating a low voltage deficit.
• Improved shelf-life stability, with devices retaining 85% efficiency after 90 days, a >20-fold increase compared to controls.

Conclusions:

• Polymers with coordinating groups, like PVP, are effective chemical additives for improving perovskite solar cell performance.
• PVP passivation enhances both the efficiency and long-term stability of perovskite solar cells.
• This approach opens new avenues for developing high-performance and stable perovskite solar cells.