Laser‐Reduced Graphene: Synthesis, Properties, and Applications

Abstract

Laser reduction of graphene oxide has attracted significant interest in recent years, because it offers a highly flexible, rapid and chemical-free graphene fabrication route that can directly write on almost any solid substrate with down to submicron feature size. Laser-reduced graphene (LRG) has been explored for various important applications such as supercapacitors, sensors, field effect transistors, holograms, solar cells, flat lenses, bolometers, thermal sound sources, cancer treatment, water purification, lithiumion batteries, and electrothermal heaters. This contribution reviews most recent research progress on the aspects of fabrication, properties and applications of LRG. Particular attention is paid to the mechanism of LRG formation, which is still debatable. The three main theories, including the photochemical process, the photothermal process, and a combination of both processes are discussed. Strategies for tuning the properties and performance of LRG, such as the laser parameters, chemical doping, structure modulation, and environment control have been highlighted. LRGs with better performance including smaller feature size, higher conductivity, and more flexible morphology design in both two-dimensional and three-dimensional format will offer tremendous opportunities for advancement in electronics, photonic, and optoelectronic applications.

A review on graphene based transition metal oxide composites and its application towards supercapacitor electrodes

“…Specific capacitance of super-capacitors is heavily influenced by carbon electrodes with a significant surface space available to electrolyte ions, porous carbon materials such as activated carbon [132], carbide-derived carbons [133,134], arranged meso-porous carbons [135,136], carbon aerogels and carbon nanotubes have been investigated as large-surface electrodes [137]. Graphene-based materials are desirable because of their elevated theoretical volume ratio (2630 m 2 g −1 and electrical conductivity) [138] as electrode materials for super-capacitors. Numerous graphene-based materials with unique chemical structures and morphologies such as chemical-modified graphene [139], microwave enhanced graphite oxide [127] (MEGO) [140] and curved graphene [141] were studied as super-capacitor's electrode components.…”

Tuning the sub-processes in laser reduction of graphene oxide by adjusting the power and scanning speed of laser

“…Compared to the thermal, chemical or plasma reduction of GO, the laser reduction method demonstrates several unique advantages, including selective and localized treatment, sub-micron feature size (down to several hundred nanometers [28]), no requirement for chemicals or heating equipment, and convenient and flexible patterning compatibility [29]. Therefore, laser reduction of GO thin film is ideal in several applications including supercapacitors [30][31][32], sensors [33][34][35], and field transistors [36], whereby reduction and device patterning can be achieved simultaneously.…”

Graphene‐Based Planar Microsupercapacitors: Recent Advances and Future Challenges

“…Compared to photolithographic processes, direct laser writing of MSCs provides a less‐process intensive fabrication and more versatile route, although limited by its serial writing mode . Some parameters, including laser power and scanning speed, would have influence on the performance of the resulted RGO, e.g., electronic conductivity .…”