Multi-pin dc glow discharge PECVD for uniform growth of vertically oriented graphene at atmospheric pressure

Atmospheric normal glow discharge plasma-enhanced chemical vapor deposition (ANGD-PECVD) holds great potential for the industrial in-line continuous growth of vertically oriented graphene (VG) nanosheets. However, conventional single-pin-to-plate electrode arrangement owns the drawback of producing a non-uniform electric field, subsequently leading to a fairly poor uniformity of the as-grown VG nanosheets. This work offers a proof of concept on a novel multi-pin ANGD-PECVD method for the uniform growth of VG nanosheets. Based on the numerical calculation, the dual-pin ANGD can provide a more uniform electric field compared with the single-pin counterpart, due to the compensation from adjacent pins and a lower integrated curvature of the discharge electrode. Experimental results demonstrate that ANGD with a four-pin discharge electrode is able to significantly improve the uniformity of the localized current density at the growth substrate, and further realize the growth of VG nanosheets with excellent homogeneity in terms of morphology and structure. Successful application of the as-grown VG nanosheets working as the active materials of a supercapacitor is illustrated at the end of this work.