Electroless Nickel Deposition: An Alternative for Graphene Contacting

Abstract

We report the first investigation into the potential of electroless nickel deposition to form ohmic contacts on single layer graphene. To minimize the contact resistance on graphene, a statistical model was used to improve metal purity, surface roughness, and coverage of the deposited film by controlling the nickel bath parameters (pH and temperature). The metalized graphene layers were patterned using photolithography and contacts deposited at temperatures as low as 60 °C. The contact resistance was 215 ± 23 Ω over a contact area of 200 μm × 200 μm, which improved upon rapid annealing to 107 ± 9 Ω. This method shows promise toward low-cost and large-scale graphene integration into functional devices such as flexible sensors and printed electronics.

Flexible Asymmetric Microsupercapacitors from Freestanding Hollow Nickel Microfiber Electrodes

“…The PS microfibers were subsequently annealed at 100 °C to provide more pronounced interfaces between microfibers and enhance film stability. This was followed by carboxylation of the PS microfibers' surfaces using KMnO 4 ; the carboxylic residues constitute nucleation sites for the subsequent electroless deposition nickel, generating a thin‐layer Ni coating . As indicated in Figure , the electroless Ni‐coated PS microfibers were further subjected to Ni electrodeposition designed to increase the stability and conductivity of the nickel layer.…”

“…An asymmetric MSC (AMSC) device was assembled, using MnO 2coated electrode as the cathode and PPy/rGO as the anode, exhibiting high areal energy density and power density, further displaying excellent mechanical stability and flexibility. [36] As indicated in Figure 1, the electroless Ni-coated PS microfibers were further subjected to Ni electrodeposition designed to increase the stability and conductivity of the nickel layer. The procedure starts with generation of PS microfibers through electrospinning, employing a PS/dimethylformamide (DMF) solution ( Figure 1A).…”

Impedance Spectroscopy of Encapsulated Single Graphene Layers

“…In either case, the detection, quantification and either elimination or optimisation of the electrode or interface resistance is imperative to optimise the performance of graphene-based devices. In the case of a metallic electrode/graphene interfaces, the exact value of the electrode resistance may depend on several factors such as the choice of the electrode material [ 38 , 39 ], the processing parameters involved with the lithography processes that is often used to pattern the electrodes [ 40 , 41 ], and the shape of the electrodes [ 42 ]. For the fabrication of electrodes, there are three main possibilities: (1) deposition of electrodes onto graphene layers (top-electrodes), (2) transfer of graphene layers onto a template with pre-defined electrodes (bottom-electrodes), or probably most promising, (3) the deposition of 1D electrodes at the edges of 2D graphene layers (side electrodes) [ 43 ].…”

Effect of Pretreatment on Magnetic Nanoparticle Growth on Graphene Surface and Magnetic Performance in Electroless Plating

“…When magnetic materials are hybridized using graphene, the combination of the recoverable characteristics of the magnetic material and the surface characteristics of graphene can maximize their utility in various applications such as recoverable catalysts [10,11]. Magnetic material@graphene hybrids are synthesized using various chemical methods [12][13][14][15][16]. However, additional reduction processes are required to obtain hybrid materials of graphene and metallic magnetic materials with higher saturation magnetization [1,11,13,17].…”

“…Electroless plating is widely used in the industry to prepare metal-coated substrates because it affords several advantages: (1) it does not require external power, unlike the electroplating method; (2) a material can be coated on an insulating substrate; and (3) metals can be coated on a substrate without an additional reduction process, unlike in other chemical synthesis methods. Studies have been conducted regarding electroless plating to grow metal nanoparticles on graphene without heat treatment [13,15,[18][19][20]. For example, nanoparticles of noble metals such as Pt, Pd, Au, and Ag have been grown on graphene via electroless plating [14,16,18,[21][22][23].…”