Cu Nanowires Passivated with Hexagonal Boron Nitride: An Ultrastable, Selectively Transparent Conductor

Abstract

Copper nanowires (Cu NWs) network are considered a promising alternative to indium tin oxide as transparent conductors for advanced optoelectronic devices. However, the fast degradation of copper in ambient conditions, largely overshadows its practical applications. Here we demonstrate a facile method for epitaxial growth of hexagonal boron nitride (h-BN) of a few atomic layers on interlaced Cu NWs by low pressure chemical vapor deposition, which exhibit excellent thermal and chemical stability under high temperature (900 °C in vacuum), high humidity (95% RH), and strong base/oxidizer solution (NaOH/H₂O₂). Meanwhile, their optical and electrical performances remain similar to those of the original Cu NWs (e.g., high optical transmittance (~93%) and high conductivity (60.9 Ω/sq)). A smart privacy glass is successfully fabricated based on [email protected] NWs network and liquid crytal, which could rapidly control the visibility from transparent to opaque (0.26 s) and at the same time, strongly block the mid-infrared light for energy saving by screening radiative heat. This precise engineering of epitaxial [email protected] core-shell nanostructure offers broad applications in high-performance electronic and optoelectronic devices.