Coffee-Ring Suppression in Inkjet-Printed Perovskite Films Enabled by a Shape-Anisotropic Nanorod Solute Strategy

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Inkjet printing offers precise deposition for functional films.
• The coffee-ring effect hinders uniform film formation in solution processing.
• Achieving high-quality perovskite films is crucial for optoelectronic devices.

Purpose of the Study:

• To develop a strategy for uniform perovskite thin films using inkjet printing.
• To overcome the coffee-ring effect in perovskite ink formulations.
• To demonstrate the potential for creating polarized perovskite films and devices.

Main Methods:

• Formulating single-solvent inks with shape-anisotropic perovskite nanorods.
• Utilizing solute engineering to control deposition dynamics.
• Characterizing film uniformity and surface roughness (average roughness Ra = 0.226 nm).

Main Results:

• Suppression of the coffee-ring effect, leading to ultraflat perovskite films.
• Formation of directionally aligned nanorod domains within the films.
• Demonstration of inkjet-printed, linearly polarized perovskite films with a polarization ratio (ρ) of 0.3357.

Conclusions:

• Shape-anisotropic nanorod engineering provides a universal route to uniform film formation.
• This strategy enables the fabrication of polarized perovskite films via inkjet printing.
• The approach is extendable to other functional materials for advanced device integration.