Manipulating Nucleation and Crystal Growth of Inorganic Perovskite Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Solid-State Chemistry

Background:

• Inorganic metal halide perovskites offer superior thermal stability for solar cells compared to hybrid organic-inorganic materials.
• Pure cesium lead triiodide (CsPbI3) has an ideal band gap but lacks phase stability in ambient conditions.
• High-quality perovskite film morphology is critical for efficient and stable perovskite solar cells.

Purpose of the Study:

• To engineer nucleation and crystal growth processes for fabricating stable and efficient inorganic perovskite films.
• To overcome the limitations of using dimethylformamide (DMF) as a single solvent for inorganic perovskite film deposition.
• To enhance the power conversion efficiency and ambient stability of inorganic perovskite solar cells.

Main Methods:

• Utilized a dimethylacetamide (DMAc)/DMF cosolvent system to promote nucleation during spin-coating.
• Introduced cesium bromide (CsBr) into dimethylammonium lead triiodide (DMAPbI3)/CsI precursors to regulate crystal growth.
• Investigated the impact of cosolvent and additive on film morphology, crystallinity, and device performance.

Main Results:

• The DMAc/DMF cosolvent system increased nucleation density and improved surface coverage.
• CsBr addition resulted in pinhole-free films with enhanced crystallinity without altering the band gap.
• Optimized inorganic perovskite solar cells achieved a power conversion efficiency of 17.67% with significantly improved ambient stability.

Conclusions:

• Nucleation and crystal growth engineering are effective strategies for improving inorganic perovskite solar cells.
• The combination of DMAc/DMF cosolvent and CsBr additive provides a viable route to high-performance and stable inorganic perovskite devices.
• This work demonstrates a pathway towards more robust and efficient inorganic perovskite solar cell technology.