Solution-process coating of vertical ZnO nanowires with ferroelectrics

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Ferroelectric materials are crucial for electronic devices.
• Coating 3D nanostructures uniformly presents significant challenges.
• Existing methods often suffer from poor step coverage and aggregation issues.

Purpose of the Study:

• To develop an improved deposition process for ferroelectrics on 3D nanostructures.
• To achieve conformal coating of ferroelectric films on ZnO nanowire arrays.
• To optimize deposition parameters for enhanced film properties and device integration.

Main Methods:

• Utilized a modified misted deposition process combining substrate and mist heating.
• Employed sputter-coated palladium (Pd) bottom electrodes on vertical ZnO nanowire arrays.
• Analyzed film morphology using scanning electron microscopy (SEM).
• Evaluated film properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and P-E hysteresis loops.

Main Results:

• Achieved conformal coating of ferroelectric Pb(Zr,Ti)O(3) (PZT) with good step coverage above 140°C.
• Substrate heating effectively prevented nanowire bundling.
• Identified an optimal substrate temperature window of 180-220°C for superior step coverage and ferroelectricity.
• Demonstrated evident ferroelectric properties in the deposited PZT films.

Conclusions:

• The modified misted deposition process is effective for coating 3D nanostructures with ferroelectrics.
• Optimized parameters yield high-quality ferroelectric films with excellent conformality.
• This advancement facilitates the integration of ferroelectric capacitors with ZnO nanowires for potential light-emitting applications.