Direct growth of graphene films without catalyst on flexible glass substrates by PECVD*

A hydrogen-plasma-etching-based plasma-enhanced chemical vapor deposition (PECVD) synthesis route without metal catalyst for preparing the graphene films on flexible glass is developed. The quality of the prepared graphene films is evaluated by scanning electron microscopy, x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. In a radio frequency (RF) power range of 50 W-300 W, the graphene growth rate increases with RF power increasing, while the intensity ratio of D- to G-Raman peak (I (D)/I (G)) decreases. When the RF power is higher than 300 W, the I (D)/I (G) rises again. By optimizing experimental parameters of hydrogen plasma etching and RF power, the properties of as-prepared flexible graphene on glass are modulated to be able to achieve the graphene's transparency, good electrical conductivity, and better macroscopic uniformity. Direct growth of graphene film without any metal catalyst on flexible glass can be a promising candidate for applications in flexible transparent optoelectronics.

Automated summary

A hydrogen-plasma-etching-based plasma-enhanced chemical vapor deposition (PECVD) synthesis route is developed for preparing graphene films on flexible glass without the need for a metal catalyst. By optimizing experimental parameters, the properties of the prepared graphene films can be modulated to achieve transparency, good electrical conductivity, and better macroscopic uniformity. This research shows that direct growth of graphene film without any metal catalyst on flexible glass can be a promising candidate for applications in flexible transparent optoelectronics.