Efficient Stabilization and Passivation for Low-Temperature-Processed γ-CsPbI₃ Solar Cells.

Area of Science:

• Materials Science
• Photovoltaics
• Solid-State Chemistry

Background:

• Inorganic CsPbI3 perovskite is crucial for photovoltaics due to its stability and band gap.
• High annealing temperatures are typically required for high-quality CsPbI3 films, limiting practical applications.
• Low-temperature fabrication of stable black-phase CsPbI3 is essential for further development.

Purpose of the Study:

• To develop a low-temperature method for synthesizing stable black-phase CsPbI3 perovskite films.
• To investigate the effect of a new additive, p-xylilenediamine bromide (PhDMADBr), on CsPbI3 film properties.
• To enhance the performance and stability of CsPbI3-based solar cells.

Main Methods:

• Solution-processed synthesis of CsPbI3 films at a low temperature of 60 °C.
• Incorporation of p-xylilenediamine bromide (PhDMADBr) as an additive.
• Characterization of film morphology, crystallinity, and phase stability.
• Fabrication and testing of perovskite solar cells (PSCs).

Main Results:

• PhDMADBr facilitates the synthesis of high-quality, stable γ-CsPbI3 films at 60 °C.
• The additive improves film morphology and crystallinity through surface anchoring and hydrogen bonding.
• Bromine incorporation passivates iodide vacancies, enhancing phase stability and device performance.
• PSCs achieved a champion efficiency of 12.71% with retained 85% efficiency after 1000 hours.

Conclusions:

• PhDMADBr is an effective additive for low-temperature fabrication of stable CsPbI3 perovskite films.
• The additive enhances both the intrinsic properties of the perovskite film and the overall device performance.
• This work presents a viable strategy for developing stable and efficient low-temperature processed CsPbI3 solar cells.