Wide-Bandgap CsPbIBr₂ Perovskite Indoor Photovoltaics Enabled by Dynamic Hot-Air Processing and FAI Interlayer...

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photovoltaics

Background:

• Inorganic halide perovskites offer excellent thermal stability and tunable optoelectronic properties for light absorption.
• Cesium lead iodobromide (CsPbIBr2) is a promising material for indoor photovoltaics (IPVs) due to its bandgap and phase stability.
• Developing uniform, defect-free CsPbIBr2 films is crucial but challenging for device performance.

Purpose of the Study:

• To enhance the structural and photovoltaic properties of CsPbIBr2 films for indoor photovoltaics.
• To investigate the synergistic effects of hot-air processing and formamidinium iodide (FAI) post-treatment.
• To optimize perovskite film quality for improved device efficiency and stability.

Main Methods:

• Synergistic strategy combining hot-air processing for controlled crystallization and FAI post-treatment for surface reconstruction.
• FAI treatment to passivate ionic defects and reduce nonradiative recombination.
• Fabrication and characterization of CsPbIBr2-based indoor photovoltaic devices.

Main Results:

• Hot-air processing facilitated uniform crystallization by controlling solvent evaporation.
• FAI post-treatment led to surface reconstruction and effective ionic defect passivation.
• Optimized CsPbIBr2 films exhibited denser microstructures, reduced lattice strain, and suppressed nonradiative recombination.
• The optimized device achieved a 7.01% power conversion efficiency under 1000 lx illumination.

Conclusions:

• Coupling thermal crystallization with mild chemical treatments is a viable strategy for improving perovskite films.
• The developed method offers a practical and scalable route for high-performance perovskite-based IPVs.
• This approach addresses key challenges in achieving high-quality inorganic halide perovskite films.