Insight into Evolution, Processing and Performance of Multi-length-scale Structures in Planar Heterojunction...

Area of Science:

• Materials Science
• Solid State Physics
• Renewable Energy

Background:

• Perovskite solar cells offer high efficiency but require precise structural control.
• Conventional characterization methods have limitations in probing hierarchical structures.
• Understanding structure-property relationships is crucial for optimizing perovskite solar cell performance.

Purpose of the Study:

• To quantitatively probe the hierarchical structure of planar heterojunction perovskite solar cells.
• To correlate processing parameters with crystallization, nano/meso-scale structure, and surface morphology.
• To provide a comprehensive understanding of film evolution for high-performance devices.

Main Methods:

• Simultaneous grazing-incidence small-angle scattering and wide-angle scattering (GISAXS/GIWAXS) techniques.
• Quantitative analysis of hierarchical structure, crystallization, and morphology.
• Correlation of structural features with processing control parameters.

Main Results:

• GISAXS/GIWAXS provided insights complementary to existing microscopic studies.
• First-time reported correlation between crystallization, orientation, internal structure, and surface morphology.
• Tunable structural transition from fractal pore network to surface fractal by chloride percentage.
• Comprehensive understanding of concurrent evolution of film morphology and crystallization.

Conclusions:

• GISAXS/GIWAXS is a powerful tool for characterizing perovskite solar cell hierarchical structures.
• Processing control significantly influences film morphology and crystallization, impacting device performance.
• The findings offer insights into formation mechanisms and guide rational synthesis design for improved perovskite solar cells.