| 1. |
- Rodriguez, Raul D., et al.
(författare)
-
Reduced Graphene Oxide Nanostructures by Light: Going Beyond the Diffraction Limit
- 2018
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1092
-
Tidskriftsartikel (refereegranskat)abstract
- Graphene oxide (GO) offers excellent possibilities that are recently demonstrated in many applications ranging from biological sensors to optoelectronic devices. The process of thermal annealing aids in removing the oxygen-containing groups in GO, making GO more graphene-like, or the so-called reduced graphene oxide (rGO). Thermal reduction can also be achieved by intense light. Here, we demonstrate a scalable, inexpensive, and environmentally friendly method to pattern graphene oxide films beyond the diffraction limit of light using a conventional laser. We show that contrary to previous reports, non-linear effects that occur under high intensity conditions of laser irradiation allow the fabrication of highly conductive carbon nanowires with dimensions much smaller than the laser spot size. The potential of this method is illustrated by the fabrication of several devices on flexible and transparent substrates, including hybrid plasmonic/rGO sensors.
|
|
| 2. |
- Banday, M. Tariq, et al.
(författare)
-
A study of recent advances in cache memories
- 2014
-
Ingår i: 2014 International Conference on Contemporary Computing and Informatics (IC3I). - 9781479966295
-
Konferensbidrag (refereegranskat)abstract
- Registers within a processor, cache within, on, or outside the processor, and virtual memory on the disk drive builds memory hierarchy in modern computer systems. The principle of locality of reference makes this memory hierarchy work efficiently. In recent years, cache organizations and designs have witnessed several advances that have not only improved their performance such as hit rates, speed, latency, energy consumption, etc. but various new designs and organizations for chip multi-processors such as multilevel caches, Non-Uniform Cache Access (NUCA), hybrid caches, etc. have also emerged. This paper presents a study of current competing processors in terms of various factors determining performance and throughput of cache organization and design. To evaluate their performance and viability, it reviews recent cache trends that include hybrid cache memory, non-uniform cache architecture, energy efficient replacement algorithms, cache memory programming, software defined caches and emerging techniques for making cache reliable against soft errors. It discusses the pros and cons of emerging cache architectures and designs.
|
|
| 3. |
- Khan, Munis, 1991, et al.
(författare)
-
High mobility graphene field effect transistors on flexible EVA/PET foils
- 2024
-
Ingår i: 2D Materials. - 2053-1583. ; 11:3
-
Tidskriftsartikel (refereegranskat)abstract
- Monolayer graphene is a promising material for a wide range of applications, including sensors, optoelectronics, antennas, EMR shielding, flexible electronics, and conducting electrodes. Chemical vapor deposition (CVD) of carbon atoms on a metal catalyst is the most scalable and cost-efficient method for synthesizing high-quality, large-area monolayer graphene. The usual method of transferring the CVD graphene from the catalyst to a target substrate involves a polymer carrier which is dissolved after the transfer process is completed. Due to often unavoidable damage to graphene, as well as contamination and residues, carrier mobilities are typically 1000–3000 cm2(Vs)−1, unless complex and elaborate measures are taken. Here, we report on a simple scalable fabrication method for flexible graphene field-effect transistors that eliminates the polymer interim carrier, by laminating the graphene directly onto office lamination foils, removing the catalyst, and depositing Parylene N as a gate dielectric and encapsulation layer. The fabricated transistors show field- and Hall-effect mobilities of 7000–10 000 cm2(Vs)−1 with a residual charge-carrier density of 2×1011 1 cm−2 at room temperature. We further validate the material quality by terahertz time-domain spectroscopy and observation of the quantum Hall effect at low temperatures in a moderate magnetic field of ∼5 T. The Parylene encapsulation provides long-term stability and protection against additional lithography steps, enabling vertical device integration in multilayer electronics on a flexible platform.
|
|
| 4. |
- Khan, Munis, 1991, et al.
(författare)
-
High mobility graphene on EVA/PET
- 2022
-
Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- Transparent conductive film on a plastic substrate is a critical component in low cost, flexible and lightweight optoelectronics. CVD graphene transferred from copper- to ethylene vinyl acetate (EVA)/polyethylene terephthalate (PET) foil by hot press lamination has been reported as a robust and affordable alternative to manufacture highly flexible and conductive films. Here, we demonstrate that annealing the samples at 60 ∘C under a flow of nitrogen, after wet etching of copper foil by nitric acid, significantly enhances the Hall mobility of such graphene films. Raman, Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the morphology and chemical composition of the graphene.
|
|
| 5. |
- Nam, Youngwoo, 1983, et al.
(författare)
-
Graphene thermocouple fabricated on a flexible and transparent substrate
- 2024
-
Ingår i: AIP Advances. - 2158-3226 .- 2158-3226. ; 14:6
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the realization of reliable, high-quality, micro-sized graphene-based field-effect devices on a flexible and transparent substrate, ethylene vinyl acetate (EVA)/polyethylene terephthalate (PET), using a convenient hot-press lamination transfer and employing parylene-N as a dielectric material for gating. Using this technique, we fabricate a graphene thermocouple on the EVA/PET substrate. Specifically, the graphene is patterned in a U-shape, and its legs are equipped with two independent top gates. Full control of the carrier density and type by electrostatic gating in the two graphene regions allow the formation of a thermocouple layout, exhibiting an enlarged thermovoltage signal when the two regions are doped with opposite types of carriers and leading to a maximum sensitivity with a thermopower of ∼73 µV/K. This agrees well with the working principle of thermocouple, and it proves the good compatibility and functionality of the graphene thermocouple on the EVA/PET substrate. Our findings suggest possible applications for producing scalable and reliable graphene-based electronic devices on flexible and transparent substrates in a simple way.
|
|
