Scalable transfer of vertical graphene nanosheets for flexible supercapacitor applications

Abstract

Vertical graphene nanosheets (VGN) are the material of choice for application in next-generation electronic devices. The growing demand for VGN-based flexible devices for the electronics industry brings in restriction on VGN growth temperature. The difficulty associated with the direct growth of VGN on flexible substrates can be overcome by adopting an effective strategy of transferring the well-grown VGN onto arbitrary flexible substrates through a soft chemistry route. In the present study, we report an inexpensive and scalable technique for the polymer-free transfer of VGN onto arbitrary substrates without disrupting its morphology, structure, and properties. After transfer, the morphology, chemical structure, and electrical properties are analyzed by scanning electron microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, and four-probe resistive methods, respectively. The wetting properties are studied from the water contact angle measurements. The observed results indicate the retention of morphology, surface chemistry, structure, and electronic properties. Furthermore, the storage capacity of the transferred VGN-based binder-free and current collector-free flexible symmetric supercapacitor device is studied. A very low sheet resistance of 670 Ω/□ and excellent supercapacitance of 158 μF cm with 86% retention after 10 000 cycles show the prospect of the damage-free VGN transfer approach for the fabrication of flexible nanoelectronic devices.

Development of an Ultra-Sensitive and Flexible Piezoresistive Flow Sensor Using Vertical Graphene Nanosheets

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Heteroatom‐Doped and Oxygen‐Functionalized Nanocarbons for High‐Performance Supercapacitors

“…In addition, one needs to ensure the better wettability of electrode by immersing it in a suitable electrolyte for at least for 12-24 h before carrying the electrochemical tests. [294] 7. Electroactive surface area versus BET surface area: The BET surface area of doped nanocarbon is in most cases different from the corresponding undoped materials.…”

Two-Dimensional Carbon: A Review of Synthesis Methods, and Electronic, Optical, and Vibrational Properties of Single-Layer Graphene

“…Unfortunately, precisely this step constitutes the weakness of CVD methods, since some residues of the protective layer keep onto graphene even after dedicated cleaning bath [24,42,119,120]. Finally, plasma-enhanced CVD has proved an excellent method to grow vertical graphene nanosheets, i.e., a special graphene morphology which features peculiar transport properties of interest for microelectronics [121][122][123]. Thermal Annealing basing on CVD method, produces graphene by using a couple or a multiple stack of an amorphous carbon layer deposited onto a metal layer (Ni, Co and Cu are the most common choices).…”