Controlled growth of carbon nanotube–graphene hybrid materials for flexible and transparent conductors and electron field emitters

Abstract

We report a versatile synthetic process based on rapid heating and cooling chemical vapor deposition for the growth of carbon nanotube (CNT)-graphene hybrid materials where the thickness of graphene and density of CNTs are properly controlled. Graphene films are demonstrated as an efficient barrier layer for preventing poisoning of iron nanoparticles, which catalyze the growth of CNTs on copper substrates. Based on this method, the opto-electronic and field emission properties of graphene integrated with CNTs can be remarkably tailored. A graphene film exhibits a sheet resistance of 2.15 kΩ sq(-1) with a transmittance of 85.6% (at 550 nm), while a CNT-graphene hybrid film shows an improved sheet resistance of 420 Ω sq(-1) with an optical transmittance of 72.9%. Moreover, CNT-graphene films are demonstrated as effective electron field emitters with low turn-on and threshold electric fields of 2.9 and 3.3 V μm(-1), respectively. The development of CNT-graphene films with a wide range of tunable properties presented in this study shows promising applications in flexible opto-electronic, energy, and sensor devices.

On the charge transfer between single-walled carbon nanotubes and graphene

“…1 It is therefore of great interest to use them in hybrid multifunctional architectures where the unique properties of both materials are utilized synergistically. Indeed there have been several recent reports in the literature on hybrids between nanotubes and graphene in a variety of different configurations, [2][3][4] and that have exhibited superior performances in applications such as energy storage and optics. [5][6][7] The nanotube/graphene hybrid devices rely on electronic interactions between the constituents, and it is important to understand these interactions at a fundamental level.…”

Harnessing light energy with a planar transparent hybrid of graphene/single wall carbon nanotube/n-type silicon heterojunction solar cell

“…We can easily understand the interaction between SCNTs and GPs. Here, GPs sheets can mend the SCNTs network by filling the tube void spaces and the SCNTs can connect the GPs sheets, so the mechanical strength of the film can be improved and the conductivity of hybrids can be greatly enhanced by the complementation between the GPs and the SCNTs [21,22]. The total area of the planar transparent membrane is larger than that of only GPs or SCNTs.…”

Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications

“…Furthermore, the necessity of high processing temperature (300−400 °C) to achieve sufficient conductance is a significant drawback for flexible optoelectronic applications employing polymer substrates. Therefore, considerable research efforts have focused on the development of alternative transparent electode materials to replace ITO, which includes carbon nanotubes [5][6][7], graphene [8][9][10], and metal nanowires [11][12][13][14].…”