Unravelling the Intrinsic Reactivity and Colloidal Instability in Tin-Based Halide Perovskite Precursor Solutions

Area of Science:

• Materials Science
• Chemical Engineering
• Solid-State Physics

Background:

• Narrow-bandgap tin and mixed tin-lead halide perovskites are promising for optoelectronic devices.
• Controlling their crystallization is crucial but challenging, hindering development.
• Existing additive engineering methods improve film formation but lack fundamental understanding.

Purpose of the Study:

• Investigate the pre-crystallization behavior of tin-based perovskite precursor solutions.
• Compare Sn-based precursors with their lead (Pb) counterparts.
• Identify fundamental origins of distinct crystallization dynamics.

Main Methods:

• Comparative structural characterization of Sn- and Pb-based perovskite precursor solutions.
• Analysis of pre-crystallization stages, including colloidal stability and agglomeration tendencies.
• Examination of solution chemistry's impact on nucleation and crystallization.

Main Results:

• Tin precursors are intrinsically more reactive and sensitive to their chemical environment than lead precursors.
• Sn-based precursors exhibit poorer colloidal stability and a stronger tendency to agglomerate.
• Small variations in solution chemistry significantly affect nucleation and crystallization dynamics, leading to a narrower processing window.

Conclusions:

• Controlling the pre-crystallization stages is vital for fabricating high-quality tin-based perovskite films via solution methods.
• Rational solvent and additive design can manage these pre-crystallization dynamics.
• Pre-crystallization engineering offers a key strategy to overcome limitations in thin-film fabrication for sustainable manufacturing.