Synthesis of Vertical Graphene Nanowalls on Substrates by PECVD as Effective EMI Shielding Materials

Abstract

Electromagnetic interference (EMI) shielding materials with low thickness and improved EMI shielding performance are highly required. Herein, by utilizing the plasma-enhanced chemical vapor deposition (PECVD) method with the optimized source power of the plasma generator, vertical graphene nanowalls (VGNs) with a relatively rapid growth rate of ∼5 μm•h −1 were prepared on substrates. The porous conductive VGNs exhibited preferable EMI shielding performance. In a frequency range of 8.2−12.4 GHz, the EMI shielding effectiveness (SE) value of VGNs with a thickness of 47.5 μm could reach 26.2 dB. In addition, VGNs with controllable thickness were also synthesized on Cu foam substrates. The combination of VGNs and Cu foam significantly improved the porosity and interfacial coupling effect of the composites. By growing VGNs with a thickness of ∼20 μm on the Cu foam, their absorption efficiency got largely enhanced by 13.8 dB (32.2%) compared with the pristine Cu foam. Subsequently, the total EMI SE of the VGNs/Cu foam composite films got enhanced by 13.5 dB (20.8%) compared with the pristine Cu foam. The VGNs and their composites with preferable EMI shielding performance establish potential for practical applications in EMI shielding.

A study of highly activated hydrogen evolution reaction performance in acidic media by 2D heterostructure of N and S doped graphene on MoOx

“…However, these approaches involve high processing temperatures, complex procedural steps, and long processing times. With this in mind, plasma‐enhanced CVD (PECVD) has been investigated to achieve a high doping/deposition level at low temperatures; this method 40 is widely preferred to avoid the use of potentially dangerous precursors 41 . Compared with the thermal‐CVD method, the presence of accelerated energetic electrons, excited molecules, atoms, free radicals, photons, and other active species in the plasma offers significant advantages such as a relatively low substrate temperature and short processing time 40 …”

“…With this in mind, plasma-enhanced CVD (PECVD) has been investigated to achieve a high doping/deposition level at low temperatures; this method 40 is widely preferred to avoid the use of potentially dangerous precursors. 41 Compared with the thermal-CVD method, the presence of accelerated energetic electrons, excited molecules, atoms, free radicals, photons, and other active species in the plasma offers significant advantages such as a relatively low substrate temperature and short processing time. 40 Herein, we propose doping the graphene structure on MoO x with S and N atoms (NSGr@MoO x ) using a plasma doping process at room temperature (RT).…”

Graphene nanowalls in photodetectors

“…Researchers have grown multilayer vertical graphene nanowalls (GNWs) to obtain a photodetection material that combines the advantageous properties of graphene with an exceptional absorption rate. [37][38][39][40][41] Similar to the CVD graphene preparation method, GNWs are typically synthesized using plasma-enhanced chemical vapor deposition (PECVD) technology. 42 They share certain similarities in photoelectric performance with graphene thin lms.…”