Transfer-free Process Research Articles

Highly responsive hydrogen sensor based on Pd nanoparticle-decorated transfer-free 3D graphene

H2 sensors play a crucial role in the development of hydrogen (H2) energy and safety monitoring. Therefore, efficiently and rapidly detecting low concentrations of H2 is a fundamental challenge that needs to be addressed in the field of H2 sensors. In this study, we present a highly sensitive H2 gas sensor based on Pd-nanoparticles (NPs)-decorated transfer-free three-dimensional (3D) graphene. 3D graphene provides an increased surface area for enhanced gas adsorption and reaction kinetics. The integration of PdNPs improved the electron transport properties, resulting in a higher sensitivity. The PdNP-decorated 3D graphene sensor exhibited a remarkable gas response of 41.9% under 3% H2 exposure. The transfer-free synthesis process ensures the excellent conductivity of 3D graphene to further enhance its overall sensing performance. These discoveries propel current gas-sensing technologies forward and introduce fresh opportunities for the development of dependable sensors that can effectively enhance industrial safety and public security.

Multilayer CVD graphene electrodes using a transfer-free process for the next generation of optically transparent and MRI-compatible neural interfaces.

Multimodal platforms combining electrical neural recording and stimulation, optogenetics, optical imaging, and magnetic resonance (MRI) imaging are emerging as a promising platform to enhance the depth of characterization in neuroscientific research. Electrically conductive, optically transparent, and MRI-compatible electrodes can optimally combine all modalities. Graphene as a suitable electrode candidate material can be grown via chemical vapor deposition (CVD) processes and sandwiched between transparent biocompatible polymers. However, due to the high graphene growth temperature (≥ 900 °C) and the presence of polymers, fabrication is commonly based on a manual transfer process of pre-grown graphene sheets, which causes reliability issues. In this paper, we present CVD-based multilayer graphene electrodes fabricated using a wafer-scale transfer-free process for use in optically transparent and MRI-compatible neural interfaces. Our fabricated electrodes feature very low impedances which are comparable to those of noble metal electrodes of the same size and geometry. They also exhibit the highest charge storage capacity (CSC) reported to date among all previously fabricated CVD graphene electrodes. Our graphene electrodes did not reveal any photo-induced artifact during 10-Hz light pulse illumination. Additionally, we show here, for the first time, that CVD graphene electrodes do not cause any image artifact in a 3T MRI scanner. These results demonstrate that multilayer graphene electrodes are excellent candidates for the next generation of neural interfaces and can substitute the standard conventional metal electrodes. Our fabricated graphene electrodes enable multimodal neural recording, electrical and optogenetic stimulation, while allowing for optical imaging, as well as, artifact-free MRI studies.

Sequential Growth of Vertical Transition-Metal Dichalcogenide Heterostructures on Rollable Aluminum Foil.

Vertical van der Waals heterostructures (vdWhs), which are made by layer-by-layer stacking of two-dimensional (2D) materials, offer great opportunities for the development of extraordinary physics and devices such as topological superconductivity, robust quantum Hall phenomenon, electron-hole pair condensation, Coulomb drag, and tunneling devices. However, the size of vdWhs is still limited to the order of a few micrometers, which restricts the large-scale roll-to-roll processes for industrial applications. Herein, we report the sequential growth of a 14 in. vertical vdWhs on a rollable Al foil via chemical vapor deposition. By supplying chalcogen precursors to liquid transition-metal precursor-coated Al foils, we grew a wide range of individual 2D transition-metal dichalcogenide (TMD) films, including MoS2, VS2, ReS2, WS2, SnS2, WSe2, and vanadium-doped MoS2. Additionally, by repeating the growth process, we successfully achieved the layer-by-layer growth of ReS2/MoS2 and SnS2/ReS2/MoS2 vdWhs. The chemically inert Al native oxide layer inhibits the diffusion of chalcogen and metal atoms into Al foils, allowing for the growth of diverse TMDs and their vdWhs. The conductive Al substrate enables the effective use of vdWhs/Al as a hydrogen evolution reaction electrocatalyst with a transfer-free process. This work provides a robust route for the commercialization of 2D TMDs and their vdWhs at a low cost.

MoS2 Synapses with Ultra-low Variability and Their Implementation in Boolean Logic.

Brain-inspired computing enabled by memristors has gained prominence over the years due to the nanoscale footprint and reduced complexity for implementing synapses and neurons. The demonstration of complex neuromorphic circuits using conventional materials systems has been limited by high cycle-to-cycle and device-to-device variability. Two-dimensional (2D) materials have been used to realize transparent, flexible, ultra-thin memristive synapses for neuromorphic computing, but with limited knowledge on the statistical variation of devices. In this work, we demonstrate ultra-low-variability synapses using chemical vapor deposited 2D MoS2 as the switching medium with Ti/Au electrodes. These devices, fabricated using a transfer-free process, exhibit ultra-low variability in SET voltage, RESET power distribution, and synaptic weight update characteristics. This ultra-low variability is enabled by the interface rendered by a Ti/Au top contact on Si-rich MoS2 layers of mixed orientation, corroborated by transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS). TEM images further confirm the stability of the device stack even after subjecting the device to 100 SET-RESET cycles. Additionally, we implement logic gates by monolithic integration of MoS2 synapses with MoS2 leaky integrate-and-fire neurons to show the viability of these devices for non-von Neumann computing.

Highly flexible all-solid-state microsupercapacitors for on chip applications using a transfer-free fabrication process

Recent research efforts in flexible electronics focus on developing lightweight, thin, and flexible micro scale supercapacitor devices integratable on a chip as power source devices. The key requirements for such devices are high performance, 2D form factor, and compatibility with thin-chip technology. We report the fabrication of an ultra-thin flexible microsupercapacitor (fMSC) based on a highly aligned horizontal array of carbon nanotube (HACNT) sheet with in-plane interdigitated configuration using a facile, single-step and scalable fabrication process. The devices exhibited, excellent flexibility under various bending states, and outstanding bending durability up to 10,000 cycles under bending angle of 180°. A representative fMSC with resolution of 40 μm showed a high peak energy density of 54 mWh cm−3. It was observed that the electrolyte deposition technique (drop-cast vs. spin-coating) affects the performance of fMSC devices. Drop-cast devices showed a higher specific capacitance (almost double) compared to spin-coated devices, but at the expense of flexibility. To demonstrate on-board integration, an array of these fMSCs was used as an energy storage unit in a vibrational energy-harvesting device, powered by a piezoelectric disk. This work demonstrates the potential of HACNT sheet based fMSCs with spin-coat electrolytes as ultra-thin microsupercapacitor devices for portable and wearable electronics.

Plasma-Enhanced Chemical Vapor Deposition of Two-Dimensional Materials for Applications

ConspectusSince the rise of two-dimensional (2D) materials, synthetic methods including mechanical exfoliation, solution synthesis, and chemical vapor deposition (CVD) have been developed. Mechanical exfoliation prepares randomly shaped materials with small size. Solution synthesis introduces impurities that degrade the performances. CVD is the most successful one for low-cost scalable preparation. However, when it comes to practical applications, disadvantages such as high operating temperature (∼1000 °C), probable usage of metal catalysts, contamination, defects, and interstices introduced by postgrowth transfer are not negligible. These are the reasons why plasma-enhanced CVD (PECVD), a method that enables catalyst-free in situ preparation at low temperature, is imperatively desirable.In this Account, we summarize our recent progress on controllable preparation of 2D materials by PECVD and their applications. We found that there was a competition between etching and nucleation and deposition in PECVD, making it highly controllable to obtain desired materials. Under different equilibrium states of the competition, various 2D materials with diverse morphologies and properties were prepared including pristine or nitrogen-doped graphene crystals, graphene quantum dots, graphene nanowalls, hexagonal boron nitride (h-BN), B-C-N ternary materials (BCxN), etc. We also used mild plasma to modify or treat 2D materials (e.g., WSe2) for desired properties.PECVD has advantages such as low temperature, transfer-free process, and industrial compatibility, which enable facile, scalable, and low-cost preparation of 2D materials with clean surfaces and interfaces directly on noncatalytic substrates. These merits significantly benefit the as-prepared materials in the applications. Field-effect transistors with high motilities were directly fabricated on graphene and nitrogen-doped graphene. By use of h-BN as the dielectric interfacial layer, both mobilities and saturated power densities of the devices were improved owing to the clean, closely contacted interface and enhanced interfacial thermal dissipation. High-quality materials and interfaces also enabled promising applications of these materials in photodetectors, pressure sensors, biochemical sensors, electronic skins, Raman enhancement, etc. To demonstrate the commercial applications, several prototypical devices were studied such as distributed pressure sensor arrays, touching module on a robot hand for braille recognition, and smart gloves for recording sign language. Finally, we discuss opportunities and challenges of PECVD as a comprehensive preparation methodology of 2D materials for future applications beyond traditional CVD.

Lysozyme Membranes Promoted by Hydrophobic Substrates for Ultrafast and Precise Organic Solvent Nanofiltration.

Organic solvent nanofiltration (OSN) is regarded as a promising separation technology in chemical and pharmaceutical industries. However, it remains a great challenge in fabricating OSN membranes with high permeability and precise selectivity by simple, transfer-free, and up-scalable processes. Herein, we report lysozyme nanofilm composite membranes (LNCM) prepared by one-step methods with hydrophobic substrates at the air/water interface. The microporous substrates not only promote the heterogeneous nucleation of amyloid-like lysozyme oligomers to construct small pores in the formed nanofilms but also benefit for the simultaneous composition of LNCM via hydrophobic interactions. The constructed nanopores are reduced to around 1.0 nm, and they are demonstrated by grazing incidence small-angle X-ray scattering with a closely packed model. The LNCM can tolerate most organic polar solvents and the permeability surpasses most of state-of-the-art OSN membranes.

Wafer-scale transfer-free process of multi-layered graphene grown by chemical vapor deposition

Chemical vapour deposition (CVD) has emerged as the dominant technique to combine high quality with large scale production of graphene. The key challenge for CVD graphene remains the transfer of the film from the growth substrate to the target substrate while preserving the quality of the material. Avoiding the transfer process of single or multi-layered graphene (SLG-MLG) has recently garnered much more interest. Here we report an original method to obtain a 4-inch wafer fully covered by MLG without any transfer step from the growth substrate. We prove that the MLG is completely released on the oxidized silicon wafer. A hydrogen peroxide solution is used to etch the molybdenum layer, used as a catalyst for the MLG growth via CVD. X-ray photoelectron spectroscopy proves that the layer of Mo is etched away and no residues of Mo are trapped beneath MLG. Terahertz transmission near-field imaging as well as Raman spectroscopy and atomic force microscopy show the homogeneity of the MLG film on the entire wafer after the Mo layer etch. These results mark a significant step forward for numerous applications of SLG-MLG on wafer scale, ranging from micro/nano-fabrication to solar cells technology.

Toward Multifunctional Electronics: Flexible NBT-Based Film with a Large Electrocaloric Effect and High Energy Storage Property.

Advances in smart and wearable devices are driving innovations in multifunctional flexible materials at a tremendous pace. Here, drawing support from the unique flexible fluorophlogopite mica platform, we present a promising all-inorganic bendable Mn-modified 0.65(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.35SrTiO3 (NBBST) film with dual use in electrocaloric (EC) refrigeration and energy storage via a cost-effective transfer-free process. An appreciable room-temperature EC effect with adiabatic temperature change of 12 K and isothermal entropy of 18 J K-1 kg-1 was realized in the NBBST film, which benefits from the large change in dipolar ordering near depolarization temperature. Also, the film exhibits a broad operating temperature span over 25 °C because of its relaxor feature. Most importantly, the film can maintain a high EC performance either under bending deformation at 5 mm radius or after undergoing 104 bending-unbending cycles. Meanwhile, the flexible NBBST film possesses good energy storage property with a recoverable energy density of 56 J cm-3 and an efficiency of 66%. This is the first example of a lead-free all-inorganic multifunctional film capacitor toward the flexible EC refrigeration and energy storage devices. This work shows bright prospects in the emerging flexible e-market.

Unusual Thermal Conductivity of Carbon Nanosheets with Self-Emerged Graphitic Carbon Dots.

The thermal conductivity (κ) of two-dimensional conducting and transparent carbon nanosheets (CNSs) prepared by a catalyst- and transfer-free process is calculated for the first time by the optothermal Raman technique. A systematic structural analysis of CNSs reveals that the thickness of polymer films affects the interaction between molecules and a Si wafer significantly, thus helping to determine the ratio of sp2 and sp3 bonding configurations of carbon (C) atoms in the CNS. Notably, the holding time of carbonization can realize a hierarchical structure with graphitic carbon dots emerging from the CNS through the rearrangement of carbon atoms, leading to the excellent κ value of 540 W/(m·K) at 310 K. It is demonstrated that an appropriate increase in carbonization time can be an effective approach for improving the ratio of sp2- to sp3-bonded C atoms in the CNS. The thermal conductivity of the CNS with the highest ratio of sp2- to sp3-bonded C atoms exhibits superior behavior and is comparable to that of reduced graphene oxide and supported graphene, respectively. Finally, when the CNS with the highest κ value of 540 W/(m·K) was applied to a heater as the heat-dissipating material, the heater showed the temperature decrease by 14 °C compared to the case without the CNS. The catalyst- and transfer-free approach for the synthesis of CNSs is highly desirable for use as heat sink materials or substrates with heat dissipation functions for extensively integrated electronic devices.

Large scale graphene/h-BN heterostructures obtained by direct CVD growth of graphene using high-yield proximity-catalytic process

We present a transfer-free process for the rapid growth of graphene on hexagonal boron nitride (h-BN) flakes via chemical vapor deposition. The growth of graphene on top of h-BN flakes is promoted by the adjacent copper catalyst. Full coverage of half-millimeter-sized h-BN crystals is demonstrated. The proximity of the copper catalyst ensures high-yield with a growth rate exceeding 2 μm min−1, which is orders of magnitude above what was previously reported on h-BN and approaches the growth rate on copper. Optical and electron microscopies along with Raman mapping indicates a two-step growth mechanism, leading to the h-BN being first covered by discontinuous graphitic species prior to the formation of a continuous graphene layer. Electron transport measurements confirm the presence of well-crystallized and continuous graphene, which exhibits a charge carrier mobility that reaches 2.0 × 104 cm2 V−1 s−1. Direct comparison of the mobility with graphene/h-BN devices obtained by wet transfer confirms an enhanced charge neutrality for the in situ grown structures.

Facile, scalable and transfer free vertical-[formula omitted] nanostructures grown on Au/[formula omitted] patterned electrode for photodetector application

Transition metal dichalcogenides such as molybdenum disulfide (MoS2) have attracted considerable attention for use in optoelectronic devices. However, their large scale monolayer production seems to be limited due to scalability, layers size and fabrication process. While, a prominent photoluminescence was reported for vertically aligned MoS2 (V-MoS2) nanosheets similar to MoS2 mono- and few- layer, as highly promising counterparts for development of optoelectronic devices. Here, we report a systematic method to fabricate V-MoS2 nanosheets using a chemical vapor deposition (CVD) technique. The growing density and morphology of V-MoS2 nanosheets are controlled by adjusting growth parameters. The V-MoS2 nanosheets form in 2H phase and have thickness of ∼10–80 nm and the lateral dimension of 1–2.5 μm. Furthermore, a photodetector platform is fabricated based on V-MoS2 nanosheets with considerable performance and transfer free process with scalable manufacturing ability. The V-MoS2 nanosheets are directly deposited on and within patterned gold leads made on SiO2 substrate to immediately form arrays of photodetector. Optical and electrical response of such a photodetector is examined at different wavelengths and light powers. Such a facile fabrication can convey to a straightforward approach for large scale and transfer free implementing V-MoS2 nanosheets in optoelectronic elements.

Large area nanometer thickness graphite freestanding film without transfer process

We fabricated the large-area (3 × 3 cm2) freestanding nanometer thickness graphite film (NGF) using transfer free process. NGF was grown on Cu foil using CVD and Cu foil is used as the frame of NGF freestanding film. Thickness of the NGF was controlled by gas flow and growth time. Transfer-free process was achieved by selective etching of Cu foil and dipping NGF in alcohol of low surface tension. Freestanding NGF reveals excellent EUV transmittance. This method allowed us to simplify the fabrication process for freestanding film without transfer process and demonstrated a possibility for HVM of pellicle for EUV lithography.

Top-Down Integration of Molybdenum Disulfide Transistors with Wafer-Scale Uniformity and Layer Controllability.

The lack of stable and efficient techniques to synthesize high-quality large-area thin films is one of the major bottlenecks for the real-world application of the 2D transition metal dichalcogenides. In this work, the growth of molybdenum disulfide (MoS2 ) on sapphire substrates by sulfurizing the MoO3 film deposited by atomic layer deposition (ALD) is reported. The advantages of the ALD method can be well inherited, and the synthesized MoS2 films exhibit excellent layer controllability, wafer-scale uniformity, and homogeneity. MoS2 films with desired thickness can be obtained by varying MoO3 ALD cycles. The atomic force microscope and Raman measurements demonstrate that the ALD-based MoS2 has good uniformity. Clear Raman shift as a function of the film thickness is observed. Field-effect transistor devices are fabricated through a transfer-free and top-down process. High On/Off current ratio (≈104 ) and medium-level electron mobilities (≈0.76 cm2 V-1 s-1 for monolayer, and 5.9 cm2 V-1 s-1 for four-layer) are obtained. The work opens up an attractive approach to realize the application of wafer-scale 2D materials in integrated circuits and systems.

Printable Transfer-Free and Wafer-Size MoS2/Graphene van der Waals Heterostructures for High-Performance Photodetection.

Two-dimensional (2D) MoS2/graphene van der Waals heterostructures integrate the superior light-solid interaction in MoS2 and charge mobility in graphene for high-performance optoelectronic devices. Key to the device performance lies in a clean MoS2/graphene interface to facilitate efficient transfer of photogenerated charges. Here, we report a printable and transfer-free process for fabrication of wafer-size MoS2/graphene van der Waals heterostructures obtained using a metal-free-grown graphene, followed by low-temperature growth of MoS2 from the printed thin film of ammonium thiomolybdate on graphene. The photodetectors based on the transfer-free MoS2/graphene heterostructures exhibit extraordinary short photoresponse rise/decay times of 20/30 ms, which are significantly faster than those of the previously reported MoS2/transferred-graphene photodetectors (0.28-1.5 s). In addition, a high photoresponsivity of up to 835 mA/W was observed in the visible spectrum on such transfer-free MoS2/graphene heterostructures, which is much higher than that of the reported photodetectors based on the exfoliated layered MoS2 (0.42 mA/W), the graphene (6.1 mA/W), and transfer-free MoS2/graphene/SiC heterostructures (∼40 mA/W). The enhanced performance is attributed to the clean interface on the transfer-free MoS2/graphene heterostructures. This printable and transfer-free process paves the way for large-scale commercial applications of the emerging 2D heterostructures in optoelectronics and sensors.

Carbon Materials Converted from PIM-1

As an effort to prepare carbon nanosheet and carbon film through catalyst- and transfer free process, several research groups have reported carbonization of polymers and small molecules such as polyacrylonitrile (PAN) and a small molecular pitch extracted from petroleum. Carbon nanosheets converted from PAN or pitch were obtained through two steps: cyclization and carbonization. Because the quality of the carbon materials sensitively depends on the cyclization conditions such as temperature, ramping rate, and oxygen contents, there is a great need for a cyclization-free process. Recently, we developed a cyclization-free carbonization process (one-step process) using PIM-1 (polymer of intrinsic microporosity). Various nano-structured PIM-1s were formed by using different methods such as electrospray, ultrasonic spray pyrolysis(USP), electrospining and spin coating methods, which were carbonized at 800~1200 oC without any catalyst. All carbonized PIM-1 maintained their original shape and their Raman spectra showed G graphitic carbon peak at 1590 cm-1 and D disordered carbon peak at 1330 cm-1. Especially, it is confirmed that carbonized PIM-1 prepared by spin coating had properties similar to graphene and could be used as the electrodes of ITO-free OSCs. Carbon nanosheets converted from PIM-1 showed a high efficiency of 1.922 % and electrical conductivity of 500 S/cm. In this presentation, shape and dimension control of carbon materials and direct use as electrodes of organic solar cells and supercapacitors will be discussed more in detail.

Catalyst-Free, Selective Growth of ZnO Nanowires on SiO2 by Chemical Vapor Deposition for Transfer-Free Fabrication of UV Photodetectors.

Catalyst-free, selective growth of ZnO nanowires directly on the commonly used dielectric SiO2 layer is of both scientific significance and application importance, yet it is still a challenge. Here, we report a facile method to grow single-crystal ZnO nanowires on a large scale directly on SiO2/Si substrate through vapor-solid mechanism without using any predeposited metal catalyst or seed layer. We found that a rough SiO2/Si substrate surface created by the reactive ion etching is critical for ZnO growth without using catalyst. ZnO nanowire array exclusively grows in area etched by the reactive ion etching method. The advantages of this method include facile and safe roughness-assisted catalyst-free growth of ZnO nanowires on SiO2/Si substrate and the subsequent transfer-free fabrication of electronic or optoelectronic devices. The ZnO nanowire UV photodetector fabricated by a transfer-free process presented high performance in responsivity, quantum efficiency and response speed, even without any post-treatments. The strategy shown here would greatly reduce the complexity in nanodevice fabrication and give an impetus to the application of ZnO nanowires in nanoelectronics and optoelectronics.

Fast Direct Growth of Self-Crystallized Graphene-from Controllable Growth to Material Characterization and Device Applications

Graphene, one of the most attractive research topics in modern science owing to its fascinating electrical properties, has been attracted much attention. Its unique structure, two-dimensional honeycomb carbon lattice, enables high conductivity and transparency. This material is thus potentially expected to become a transparent conductive layer in optoelectrical applications and thus stimulates a lot of studies on the synthetic growth methods to requisitely develop high uniformity with high quality and simple process for industrial manufactory. Common process for the synthesis of the graphene is typically based on heat chemical vapour deposition (CVD), for which carbon sources such as methane and acetylene are as precursors with metal-catalytic layers such as Cu or Ni foils. However, an additional complex transferred processes of the graphene layer on an insulator substrate from the metal-mediated layer are imperative steps for the device application, containing spinning coating of protective layer, etching of mediated layer, fishing of graphene layer, and removal of protective layer. Defects, such as cracks, wrinkles, and chemical residuals (Fe3+, polymer…etc.) can be readily formed during transferred processes, resulting in decease of electron mobility due to scattering behaviours by defects, thereby degrading device performance. Many transfer-free processes had been investigated to prevent these problems. The concept of back-side segregation by bulk or boundary diffusion had been applied to achieve the segregated graphene at interface between the substrate and the metal-mediated layer. In this talk, a directly self-crystallized graphene layer with transfer-free process on arbitrary insulator by Ni vapor-assisted growth at growth temperatures between 950 to 1100 ºC via conventional chemical vapor deposition (CVD) system was developed and demonstrated. Domain sizes of graphene were confirmed by Raman spectra from ~12 nm at growth temperature of 1000 ºC to ~32 nm at growth temperature of 1100 ºC, respectively. Furthermore, the thickness of the graphene is controllable, depending on deposition time and growth temperature. In addition, we also develop a new method to synthesize graphene and highly oriented graphite via Ni-catalyzed solid phase segregation using amorphous carbon as a resource by the rapid microwave heating process (RMHP) in air. By controlling input powers of the microwave, the annealing temperature could be controlled, enabling this synthesis to dissolve the carbon atoms into catalyst layer. With annealing under an adequate temperature in air, the carbon solute in the Ni will retard the formation of the NiO film on the surface by reduction process.

Direct growth of self-crystallized graphene and graphite nanoballs with Ni vapor-assisted growth: From controllable growth to material characterization

A directly self-crystallized graphene layer with transfer-free process on arbitrary insulator by Ni vapor-assisted growth at growth temperatures between 950 to 1100°C via conventional chemical vapor deposition (CVD) system was developed and demonstrated. Domain sizes of graphene were confirmed by Raman spectra from ~12 nm at growth temperature of 1000°C to ~32 nm at growth temperature of 1100°C, respectively. Furthermore, the thickness of the graphene is controllable, depending on deposition time and growth temperature. By increasing growth pressure, the growth of graphite nano-balls was preferred rather than graphene growth. The detailed formation mechanisms of graphene and graphite nanoballs were proposed and investigated in detail. Optical and electrical properties of graphene layer were measured. The direct growth of the carbon-based materials with free of the transfer process provides a promising application at nanoelectronics.

Transfer free suspended graphene devices on silicon using electrodeposited copper

Transfer free processes using Cu films greatly simplify the fabrication of reliable suspended graphene devices. In this paper, the authors report on the use of electrodeposited Cu films on Si for transfer free fabrication of suspended graphene devices. The quality of graphene layers on optimized electrodeposited Cu and Cu foil are found to be the same. By selectively etching the underlying Cu, the authors have realized by a transfer free process metal contacted, suspended graphene beams up to 50 μm in length directly on Si. The suspended graphene beams do not show any increase in defect levels over the as grown state indicating the efficiency of the transfer free process. Measured room temperature electronic mobilities of up to 5200 cm2/V·s show that this simpler and CMOS compatible route has the potential to replace the foil based route for such suspended nano and micro electromechanical device arrays.