Photo-Physics and Renewable Energy Applications of Single-Walled Carbon Nanotubes

submitted by: RASEIBoulder
Summary: Single-walled carbon nanotubes (SWNTs) are two-dimensionally confined quantum wires that have the potential to impact a variety of renewable energy applications. SWCNTs have several fundamental properties that make them attractive for sustainable energy conversion technologies, including high electron and hole mobilities, size-tunable ionization potentials and electron affinities in an energy range relevant to many photovoltaic devices, and optical transitions in the visible and...

Stable Aqueous Dispersions of Non-Covalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications

submitted by: Swastik

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Authors: An Xiahong, Trevor Simmons, Swastik Kar, Saikat Talapatra, Rakesh Shah, Christopher Wolfe, Kim m. Lewis, Morris Washington, Saroj k. Nayak

Ternary Self-Assembly of Ordered Metal Oxide-Graphene Nanocomposites for Electrochemical Energy Storage

submitted by: liu.aksay
Surfactant or polymer directed self-assembly has been widely investigated to prepare nanostructured metal oxides, semiconductors, and polymers, but this approach is mostly limited to two-phase materials, organic/inorganic hybrids, and nanoparticle or polymer-based nanocomposites. Self-assembled nanostructures from more complex, multiscale, and multiphase building blocks have been investigated with limited success. Here, we demonstrate a ternary self-assembly approach using graphene as...
Authors: Donghai Wang, Rong Kou, Daiwon Choi, Zhenguo Yang, Zimin Nie, Juan Li, Laxmikant v. Saraf, Dehong Hu, Jiguang Zhang, Gordon l. Graff, Jun Liu, Michael a. Pope, Ilhan a. Aksay

Graphene and Mobile Ions: The Key to All-Plastic, Solution-Processed Light-Emitting Devices

submitted by: NateRobinson
The emerging field of “organic” or “plastic” electronics has brought low-voltage, ultrathin, and energy-efficient lighting and displays to market as organic light-emitting diode (OLED) televisions and displays in cameras and mobile phones. Despite using carbon-based materials as the light-emitting layer, previous efficient organic electronic light-emitting devices have required at least one metal electrode. Here, we utilize chemically derived graphene for the transparent cathode in...
Authors: Ludvig Edman, Manish Chhowalla, Goki Eda, Hisato Yamaguchi, Piotr Matyba, Nathaniel d. Robinson

Graphene field effect transistors with high on/off current ratio and large transport band gap at room temperature

submitted by: liting231
Graphene is considered to be a promising candidate for future nanoelectronics due to its exceptional electronic properties. Unfortunately, the graphene field-effect transistors (FETs) cannot be turned off effectively due to the absence of a band gap, leading to an on/off current ratio typically around 5 in top-gated graphene FETs. On the other hand, theoretical investigations and optical measurements suggest that a band gap up to a few hundred millielectronvolts can be created by the...
Authors: Fengnian Xia

High Mobility, Printable, and Solution-Processed Graphene Electronics

submitted by: Priscilla
The ability to print graphene sheets onto large scale, flexible substrates holds promise for large scale, transparent electronics on flexible substrates. Solution processable graphene sheets derived from graphite can form stable dispersions in solutions and are amenable to bulk scale processing and ink jet printing. However, the electrical conductivity and carrier mobilities of this material are usually reported to be orders of magnitude poorer than that of the mechanically cleaved...
Authors: Shuai Wang, Priscilla kailian Ang, Ziqian Wang, Ai ling lena Tang, John t. l. Thong, Kian ping Loh

Direct Chemical Vapor Deposition of Graphene on Dielectric Surfaces

submitted by: ygzhang
Direct deposition of graphene on various dielectric substrates is demonstrated using a single-step chemical vapor deposition process. Single-layer graphene is formed through surface catalytic decomposition of hydrocarbon precursors on thin copper films predeposited on dielectric substrates. The copper films dewet and evaporate during or immediately after graphene growth, resulting in graphene deposition directly on the bare dielectric substrates. Scanning Raman mapping and spectroscopy,...
Authors: Yuegang Zhang

Wafer-Scale Synthesis and Transfer of Graphene Films

submitted by: Youngbin.Lee
We developed means to produce wafer scale, high-quality graphene films as large as 3 in. wafer size on Ni and Cu films under ambient pressure and transfer them onto arbitrary substrates through instantaneous etching of metal layers. We also demonstrated the applications of the large-area graphene films for the batch fabrication of field-effect transistor (FET) arrays and stretchable strain gauges showing extraordinary performances. Transistors showed the hole and electron mobilities of the...
Authors: Youngbin Lee, Sukang Bae, Houk Jang, Sukjae Jang, Shou-en Zhu, Sung hyun Sim, Young il Song, Byung hee Hong, Jong-hyun Ahn

Supercapacitors Based on Flexible Graphene/Polyaniline Nanofiber Composite Films

submitted by: qwu
Composite films of chemically converted graphene (CCG) and polyaniline nanofibers (PANI-NFs) were prepared by vacuum filtration the mixed dispersions of both components. The composite film has a layered structure, and PANI-NFs are sandwiched between CCG layers. Furthermore, it is mechanically stable and has a high flexibility; thus, it can be bent into large angles or be shaped into various desired structures. The conductivity of the composite film containing 44% CCG (550 S/m) is about 10...
Authors: Qiong Wu, Yuxi Xu, Zhiyi Yao, Anran Liu, Gaoquan Shi

P25-Graphene Composite as a High Performance Photocatalyst

submitted by: Jinghong_Li
Herein we obtained a chemically bonded TiO2 (P25)-graphene nanocomposite photocatalyst with graphene oxide and P25, using a facile one-step hydrothermal method. During the hydrothermal reaction, both of the reduction of graphene oxide and loading of P25 were achieved. The as-prepared P25-graphene photocatalyst possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously, which was rarely reported in other TiO2-carbon...
Authors: Jinghong Li, Hao Zhang, Xiaojun Lv, Yueming Li, Ying Wang