Controlled growth of CH$_3$NH$_3$PbI$_3$ nanowires in arrays of open nanofluidic channels

TL;DR

This paper demonstrates a novel graphoepitaxial liquid-solid growth method for fabricating large-area, well-controlled CH$_3$NH$_3$PbI$_3$ nanowire arrays in open nanofluidic channels, advancing perovskite device manufacturing.

Contribution

It introduces a new controlled growth technique for perovskite nanowires in open channels, enabling scalable fabrication of nanowire arrays with precise size and orientation control.

Findings

Achieved mm²-sized perovskite nanowire surfaces with controlled morphology.

Real-time visualization of nanowire growth process.

Potential for scalable optoelectronic device fabrication.

Abstract

Spatial positioning of nanocrystal building blocks on a solid surface is a prerequisite for assembling individual nanoparticles into functional devices. Here, we report on the graphoepitaxial liquid-solid growth of nanowires of the photovoltaic compound CH$_3$NH$_3$PbI$_3$ in open nanofluidic channels. The guided growth, visualized in real-time with a simple optical microscope, undergoes through a metastable solvatomorph formation in polar aprotic solvents. The presently discovered crystallization leads to the fabrication of mm2-sized surfaces composed of perovskite nanowires having controlled sizes, cross-sectional shapes, aspect ratios and orientation which have not been achieved thus far by other deposition methods. The automation of this general strategy paves the way towards fabrication of wafer-scale perovskite nanowire thin films well-suited for various optoelectronic devices, e.g. solar cells, lasers, light-emitting diodes and photodetectors.