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Journal ArticleDOI

A composite layer of atomic-layer-deposited Al2O3 and graphene for flexible moisture barrier

01 May 2017-Carbon (Pergamon)-Vol. 116, pp 553-561
TL;DR: In this paper, a composite layer of atomic layer-deposition-grown Al 2 O 3 on CVD graphene was fabricated for encapsulation of an organic light-emitting diode (OLED).
About: This article is published in Carbon.The article was published on 2017-05-01. It has received 40 citations till now. The article focuses on the topics: Graphene oxide paper & Graphene foam.
Citations
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Journal ArticleDOI
TL;DR: Two dimensional (2D) graphene and its derivatives modification with nanomaterials for formation of hybrid/nanocomposites undergo stimulus-induced optical and electrical changes which are important.
Abstract: Two dimensional (2D) graphene and its derivatives modification with nanomaterials for formation of hybrid/nanocomposites undergo stimulus-induced optical and electrical changes which are important ...

106 citations

Journal ArticleDOI
Eun Gyo Jeong1, Jeong Hyun Kwon1, Kisuk Kang1, Soyeong Jeong1, Kyung Cheol Choi1 
TL;DR: In this paper, various state-of-the-art component technologies, including thin-film transistors (TFTs), electrodes, thinfilm encapsulations (TFE...
Abstract: As the demand for flexible, rollable, and foldable displays grows, various state-of-the-art component technologies, including thin-film transistors (TFTs), electrodes, thin-film encapsulations (TFE...

74 citations

Journal ArticleDOI
01 Jan 2019-JOM
TL;DR: In this article, the authors introduce various organic deposition methods and mechanisms for enhancing barrier performance, such as modulating the internal stress in TFEs to increase flexibility by adopting other layers that can reduce internal stress.
Abstract: Recent trends in thin film encapsulations (TFEs), fabricating organic/inorganic encapsulation films are reviewed. Atomic layer deposited inorganic films have superior barrier performance and have advantages of excellent uniformity over large scales at relatively low deposition temperatures. However, organic film should be combined with a hybrid structure for improved flexibility and longer lag time. We introduce various organic deposition methods and mechanisms for enhancing barrier performance. However, stress engineering is required to achieve high performance TFEs for flexible devices, new materials and deposition methods. First, modulating the internal stress in TFEs should be considered to increase flexibility by adopting other layers that can reduce internal stress. Second, controlling the configuration of the hybrid structure can prevent degradation due to cracks. Third, the introduction of a neutral plane as the middle layer decreases the strain. The results summarize how the device can improve barrier performance under external stress. This paper can guide the improvements in barrier performance.

72 citations

Posted Content
TL;DR: In this paper, perylene tetracarboxylic acid (PTCA) was used to functionalize graphene surface and selectively introduced densely packed surface groups on graphene, which could be used to integrate ultrathin high-k dielectrics in future graphene electronics.
Abstract: We investigate Atomic Layer Deposition (ALD) of metal oxide on pristine and functionalized graphene. On pristine graphene, ALD coating can only actively grow on edges and defect sites, where dangling bonds or surface groups react with ALD precursors. This affords a simple method to decorate and probe single defect sites in graphene planes. We used perylene tetracarboxylic acid (PTCA) to functionalize graphene surface and selectively introduced densely packed surface groups on graphene. Uniform ultrathin ALD coating on PTCA graphene was achieved over large area. The functionalization method could be used to integrate ultrathin high-k dielectrics in future graphene electronics.

65 citations

Journal ArticleDOI
TL;DR: In this paper, the authors employed atomic layer deposition (ALD) to form Al2O3 layer as an encapsulant for perovskite solar cells (PSCs).

58 citations

References
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Journal ArticleDOI
TL;DR: Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena can now be mimicked and tested in table-top experiments.
Abstract: Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

35,293 citations

Journal ArticleDOI
Changgu Lee1, Xiaoding Wei1, Jeffrey W. Kysar1, James Hone2, James Hone1 
18 Jul 2008-Science
TL;DR: Graphene is established as the strongest material ever measured, and atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.
Abstract: We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.

18,008 citations

Journal ArticleDOI
05 Jun 2009-Science
TL;DR: It is shown that graphene grows in a self-limiting way on copper films as large-area sheets (one square centimeter) from methane through a chemical vapor deposition process, and graphene film transfer processes to arbitrary substrates showed electron mobilities as high as 4050 square centimeters per volt per second at room temperature.
Abstract: Graphene has been attracting great interest because of its distinctive band structure and physical properties. Today, graphene is limited to small sizes because it is produced mostly by exfoliating graphite. We grew large-area graphene films of the order of centimeters on copper substrates by chemical vapor deposition using methane. The films are predominantly single-layer graphene, with a small percentage (less than 5%) of the area having few layers, and are continuous across copper surface steps and grain boundaries. The low solubility of carbon in copper appears to help make this growth process self-limiting. We also developed graphene film transfer processes to arbitrary substrates, and dual-gated field-effect transistors fabricated on silicon/silicon dioxide substrates showed electron mobilities as high as 4050 square centimeters per volt per second at room temperature.

10,663 citations

Journal ArticleDOI
TL;DR: The roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates are reported, showing high quality and sheet resistances superior to commercial transparent electrodes such as indium tin oxides.
Abstract: The outstanding electrical, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as approximately 125 ohms square(-1) with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as approximately 30 ohms square(-1) at approximately 90% transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain.

7,709 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that micrometre-size sensors made from graphene are capable of detecting individual events when a gas molecule attaches to or detaches from graphene's surface.
Abstract: The ultimate aim of any detection method is to achieve such a level of sensitivity that individual quanta of a measured entity can be resolved. In the case of chemical sensors, the quantum is one atom or molecule. Such resolution has so far been beyond the reach of any detection technique, including solid-state gas sensors hailed for their exceptional sensitivity1, 2, 3, 4. The fundamental reason limiting the resolution of such sensors is fluctuations due to thermal motion of charges and defects5, which lead to intrinsic noise exceeding the sought-after signal from individual molecules, usually by many orders of magnitude. Here, we show that micrometre-size sensors made from graphene are capable of detecting individual events when a gas molecule attaches to or detaches from graphene's surface. The adsorbed molecules change the local carrier concentration in graphene one by one electron, which leads to step-like changes in resistance. The achieved sensitivity is due to the fact that graphene is an exceptionally low-noise material electronically, which makes it a promising candidate not only for chemical detectors but also for other applications where local probes sensitive to external charge, magnetic field or mechanical strain are required.

7,318 citations