Halide Perovskite Crystallization Processes and Methods in Nanocrystals, Single Crystals, and Thin Films

Area of Science:

• Materials Science
• Solid-State Chemistry
• Nanotechnology

Background:

• Halide perovskites exhibit exceptional optoelectronic properties, driving research for applications in light emission, detection, and harvesting.
• Device performance is critically dependent on the crystal quality of halide perovskite materials.
• Nucleation and crystal growth processes fundamentally dictate crystal quality.

Purpose of the Study:

• To provide a fundamental understanding of halide perovskite crystallization driven by solution supersaturation.
• To summarize methods for preparing halide perovskite nanocrystals, single crystals, and thin films.
• To correlate crystallization processes with the resulting material morphology and device performance.

Main Methods:

• Discussion of supersaturation's role in controlling nucleation and crystal growth thermodynamics.
• Analysis of homogeneous and heterogeneous nucleation pathways.
• Review of strategies for achieving nucleation-dominated (nanocrystals), growth-dominated (single crystals), and mixed (thin films) processes.

Main Results:

• Supersaturation dictates the Gibbs free energy changes for aggregation and nucleation.
• A minimum critical concentration (Cmin) is required to induce homogeneous nucleation.
• Thermodynamics favor crystal growth and heterogeneous nucleation over homogeneous nucleation.
• Specific concentration regimes relative to Cmin and solubility enable targeted synthesis of different morphologies.

Conclusions:

• Controlling supersaturation is paramount for tailoring halide perovskite crystal formation.
• Nucleation-dominated processes yield nanocrystals, growth-dominated processes yield single crystals, and compromised processes yield thin films.
• This understanding facilitates the rational design of high-performance halide perovskite-based devices.