Pei, chengzhi cai, chiming yam, and quoting qin, us patent number 7,637,960 issued on. The h 2 production rate increases with increasing pt content to a plateau at around 24%, beyond which it decreases again. Vapour phase kinetic uptake experiments were performed on the ta vtisa microbalance. The strong interest in graphene has motivated the scalable production of high quality graphene and graphene devices. Large singlecrystalline graphene monolayers have been synthesized on a cuni alloy using a local precursor feeding method with an enhanced growth rate. Designer spoof surface plasmon structures collimate.
This page introduce you to aimr research activities. A facile oxidation visualization method was applied to study the nucleation density and morphology of graphene domains on copper foils. Chen, control and characterization of individual grains and grain boundaries in graphene grown by chemical vapour deposition, nature materials, 10, 443 2011. Extreme light management in mesoporous wood cellulose paper for optoelectronics. Yu received his phd degree in electrical engineering from the university of houston. All content 201020, the university of texas at austin, department of mechanical engineering. Vertically stacked multiheterostructures of layered.
Zongfu yu is recognized as a thomson reuters highly cited researcher, defined as the top 1% by citations for their field and are making an impact in solving the worlds biggest challenges multimodal detector and visual perception. While many systems show chromic responses to applied stimuli, few show distinct multicolored states within the same system and exhibit limited flexibility in manipulation of the stimuli source. The singlecrystal nature of the graphene grains is verified by electron. Graphenes float on the surface of water owing to its hydrophobic nature. Pdf 20 nature nanotech jiminzhao efficient solar water. Center for advanced materials and department of electrical and computer engineering. Jauregui, wei wu, robert colby, jifa tian, zhihua su, helin cao, zhihong liu, deepak pandey, dongguang wei, ting fung chung, peng peng, nathan p. Ruoff, direct delamination of graphene for highperformance plastic electronics small, wiley online library, september 20. Control and characterization of individual grains and grain. We report on simultaneous thermoelectric power and fourprobe resistance measurements of chemical vapor deposition grown graphene during a degas process, as well as in exposure to various gases. Controllable synthesis of submillimeter singlecrystal.
Colin preston, wenxin wu, peng peng, nathaniel jang, qingkai yu, zongfu yu, liangbing hu. The catalyst is used in the design of a single photochromic system that can be tuned to exhibit response to changes in the properties of the applied light. Multicolor reversible photochromisms via tunable light. Growth of single crystal graphene arrays by locally controlling. Preparation of layernumber controlled graphene cvd is a popular and mature method for synthesizing high quality graphene layers on cu. A typical time course of h 2 production using 3 wt% ptdeposited gc 3. Robert colbys 15 research works with 1,292 citations and 3,597 reads, including. Jonathan fan, kui bao, chihhui wu, jiming bao, rizia bardhan, naomi halas, vinothan n. Ba in physics, national taiwan university, taiwan, china 1970.
Qingkai yu, xiaojun cai, jimin zhao, zhifeng ren, hui fang, francisco robleshernandez, steven baldelli and jiming bao 74 hierarchical assembly of metal nanoparticles, quantum dots and organic dyes using dna origami scaffolds robert schreiber, jaekwon do, evamaria roller, tao zhang, verena j. Tianru wu, xuefu zhang, qinghong yuan, jiachen xue, guangyuan lu, zhihong liu, huishan wang, haomin wang, feng ding, qingkai yu, xiaoming xie and mianheng jiang, fast growth of inchsized singlecrystalline graphene from a controlled single nucleus on cuni alloys, nature materials, 15, 1, 43, 2016. Graphene is a oneatomthick layer of carbon that was first fabricated in 2004. Nov 23, 2015 a modified chemical vapour deposition setup allowing extremely localized injection of carbon precursors on a cuni substrate is used for the fast growth of largearea singlecrystalline. A highly active oxygen vacant titanium dioxidereduced graphene oxide photocatalyst that exhibits significantly enhanced photochromic performance and high cyclability is reported. Quantum hall effect on centimeter scale chemical vapor. All the cvd processes were conducted in a homebuilt cvd system that consists of a quartz tube furnace connected to a mechanical pump and gas manifolds.
Submillimeter singlecrystal monolayer and multilayer graphene domains were prepared by an atmospheric pressure chemical vapor deposition method with suppressing nucleation on copper foils through an annealing procedure. This insight paves the way for approaches to enhance the efficiency of nanomedicine delivery by harnessing active transport mechanisms, and encourage researchers to rethink how tumours are treated. Extrinsic green photoluminescence from the edges of 2d cesium. Method for creating singlecrystal arrays of graphene. Qingkai yu is currently a research assistant professor of electrical engineering and project leader in center for advanced materials in the university of houston. Pdf deformation and fracture behavior of bicrystal graphene. Characteristics of graphene for quantized hall effect. Lowdimensional materials the orcid identification numbers for the authors of this article.
Using these seeds, we can grow an ordered array of thousands or millions of single crystals of graphene, said qingkai yu, the papers first author. Eric andrew stach is an american materials scientist who is currently a professor at the university of pennsylvania and an elected fellow of both the american physical society for development and application of insitu and operando methods in materials research using transmission electron microscopy and the microscopy society of america. Thermoelectric power of graphene as surface charge doping. Structural and electronic properties of highly doped topological insulator bi2se3 crystals. Novoselov, the rise of graphene, nature materials 6 2007. Pdf singlecrystal grains and grain boundaries in graphene. Four devices are achieved that can respond to changes in. Plasmons in graphene moire superlattices nature materials. Center for advanced materials, electrical and computer engineering. Uh researchers graphene development published in nature. Control and characterization of individual grains and grain boundaries in graphene grown by. Designer spoof surface plasmon structures collimate terahertz laser beams nanfang yu1, qi jie wang1, mikhail a. As a content of 25% ni results in a concentration that is larger than the percolation threshold of fcc materials, networks of long ni chains are. These authors contributed equally to this work affiliations center for advanced materials and department of electrical and computer engineering, university of.
Center for advanced materials, electrical and computer engineering, university of. Xia lu school of materials, sun yatsen university verified email at mail. Pdf deformation and fracture behavior of bicrystal. Deepak pandeys research works purdue university, in. Waferscale synthesis of graphene by chemical vapor deposition and its application in hydrogen sensing. Xia, shell buckling of imperfect multiwalled carbon nanotubesexperiments and analysis, experimental mechanics, 47, 153161 2007 link to pdf file. Nonmagnetic quantum emitters in boron nitride with. Longb liao, qiuhui zhang, zhihua su, zhongzheng zhao, yanan wang, yang li, xiaoxiang lu, dongguang wei, guoying feng, qingkai yu, xiaojun cai, jimin zhao, zhifeng ren, hui fang, francisco robles hernandez, steven baldelli, and jiming bao, highefficiency solar water splitting using a nanocrystalline coo photocatalyst, nature. The synthesis of ordered arrays of gscs by regrowth from prepatterned seed crystals that offer an approach for scalable fabrication of single crystal graphene devices while avoiding domain boundaries is demonstrated herein. Fabrication of singlecrystalline graphene arrays, qingkai yu, s. Coc700 made from an extended depth of field reconstruction. We hope that industry will look at these findings and consider the ordered arrays as a possible means of fabricating electronic devices.
The university of texas at austin, 2016 supervisor. Phasechange memory materials have stimulated a great deal of interest although the sizedependent behaviors have not been well studied due to the lack of method for producing their nanoscale structures. Helin cao, qingkai yu, robert colby, deepak pandey, c. It is the thinnest material known, but it is exceedingly strong, light and flexible. Jiaqi dai, yonggang yao, fei shen, colin preston, wenxin wu, peng peng, nathaniel jang, qingkai yu, zongfu yu, and liangbing hu. How low nucleation density of graphene on cuni alloy is achieved. The dependence of fracture strength, strain as well as youngs moduli on different stgbs were examined. The ones marked may be different from the article in the profile. His research interests include materials synthesis, nanofabrication and nanodevices. Richter,2 randolph elmquist,2 david newell,2 and yong p. Carlton grant willson graphene, a single layer of sp2 hybridized carbon atoms, was first isolated from graphite in 2004.
Jauregui1, wei wu2, robert colby2, jifa tian2, zhihua su. Explaining the properties and performance of practical nanotube devices and related applications, this is the first introductory textbook on the subject. Robert colbys research works purdue university, in. Due to the discontinuous nature of the 2d gan, an exact dielectric function for the 2d gan layer could not be established. Graphene segregated on ni surfaces and transferred to insulators qingkai yu center for advanced materials, electrical and computer engineering, university of houston, houston, texas 77204 jie lian department of mechanical, aerospace and nuclear engineering, rensselaer polytechnic institute, troy, new york 12180 sujitra siriponglert.
Atomicscale investigation of graphene grown on cu foil. Fabrication of singlecrystalline graphene arrays yu qingkai. Waferscale synthesis of graphene by chemical vapor. The outstanding electrical1, mechanical2,3 and chemical4,5 properties of graphene make it attractive for applications in flexible electronics6,7,8. Xiaohan wang, li tao, yufeng hao, zhihong liu, harry chou, iskandar kholmanov, shanshan chen, cheng tan, nishant jayant, qingkai yu, deji akinwande, rodney s. Twodimensional gallium nitride realized via nature. Smart materials are able to reversibly respond to one or more environmental stimuli for example, chemical, electrical, light, temperature and mechanical. Due to negative charge transfer from the buffer layer, monolayer siface eg has carrier density values.
Search purdue news academics athletics rankings general. The chalcogel como 3 s is obtained from the reaction of nh 4 2 mo 3 s with cobalt acetate in solution. However, cunning refinements in growth techniques push the limits to obtain supersized singlecrystal domains. It is now shown thatthrough the use of seedshighquality, large, singlecrystal domains can be grown on a. Here, we show that optical emission from individual quantum emitters in hbn is spatially correlated with structural defects and can display ultranarrow zerophonon line width down to 45. Continuous production of graphite nanosheets by bubbling. Builtin electric field minimization in in, ga n nanoheterostructures. Chemical vapor deposition cvd has emerged as an important method for the preparation and production of graphene for various applications since the method was first reported in 20082009.
Figure 7 broad utility of xpl materials platform space is depicted by the range of tensile moduli and the corresponding fracture strains achieved by modifying three materials design. However, bilayer graphene samples have been limited to. The development reported in nature materials marks a step towards perfecting such a method. Colleges of science and engineering materials planning materials.
Jauregui 1, wei wu 2, robert colby 2, jifa tian 2, zhihua su, helin cao, zhihong liu, deepak pandey, dongguang wei, ting fung chung, peng peng, nathan guisinger, eric a. Publications nanomaterials and multiscale modeling. Hexagonal boron nitride hbn is an emerging material in nanophotonics and an attractive host for color centers for quantum photonic devices. Chen and qingkai yu ab figure 1 production of large, flexible and transparent graphene. Graphene segregated on ni surfaces and transferred to insulators. Figure 4 from atomicscale investigation of graphene grown. Deepak pandeys 11 research works with 1,470 citations and 3,297 reads, including. Xia, yibo nian, and shinshem pei, mechanism of horizontally aligned growth of singlewall carbon nanotubes on r. China academy of sciences overview the 3rd graphene flagship eu. Since its debut in 2004, graphene has attracted enormous interest because of its unique properties. Optical transparency, tunable conducting properties and easy processability make metal oxides key materials for advanced optoelectronic devices. Chen, control and characterization of individual grains and grain boundaries in graphene grown by chemical.
Review of chemical vapor deposition of graphene and. Park, jie lian, dmitry zemlyanov, isaac childres, vladimir drachev, eric a. Wei wu1,2, qingkai yu1,3, peng peng2, zhihong liu3, jiming bao2 and. Two different types of stgbs graphene mainly zigzag and armchair types were investigated. New evidence suggests that the mechanism of nanoparticle entry into solid tumours may be driven by an active process. Control and characterization of individual grains and. Control and characterization of individual grains and grain boundaries in graphene grown by chemical vapour deposition. Chemical vapour deposition is a promising route for largescale graphene growth. Since largescale graphene films synthesized to date are typically polycrystalline, it is important to characterize and control grain boundaries, generally believed to degrade graphene quality. Huishan wang1, haomin wang1, feng ding5, qingkai yu3, xiaoming xie1,6, mianheng jiang1,6 1state key laboratory of functional materials for informatics, shanghai institute of microsystem and information technology, chinese academy of sciences. Findings are detailed in a research paper appearing online this week and in the june issue of nature materials. Nirajan mandel has won 1st place award for his poster presentation at 2015 nsac graduate student research symposium held in birck nanotechnology center, which drew graduate student participants from multiple departments working on nano related research, congratulations. Continuous production of graphite nanosheets by bubbling chemical vapor deposition using molten copper yongliang tang, peng peng, shuangyue wang, zhihong liu, xiaotao zu, and qingkai yu. This cited by count includes citations to the following articles in scholar.
For all investigated samples, a dramatic change in thermoelectric power was observed and found to be sensitive to the gas molecule charge doping on the surface of graphene. The discovery of electric field induced band gap opening in bilayer graphene opens a new door for making semiconducting graphene without aggressive size scaling or using expensive substrates. Advanced search citation search login register advanced materials. Quantum hall effect on centimeter scale chemical vapor deposited graphene films tian shen,1,2,a wei wu,3 qingkai yu,3,b curt a. New electronics material closer to commercial reality 26 may 2011, by emil venere this scanning electron microscope picture shows individual crystal grains in an array of a material called. Pei uh department of electrical and computer engineering. Fabrication of short and thin silicon cantilver tips for afm with soi wafers, qingkai yu, s. Aimr has been engaged in a wide range of activities such as fundamental researches by providing mathematical tools,which can help make sense of experimental results materials science research, as well as developing a. A modified chemical vapour deposition setup allowing extremely localized injection of carbon precursors on a cuni substrate is used for the fast growth of largearea singlecrystalline. Graphenehbn moire superlattices exhibit a new set of dirac minibands, whose interband transitionstogether with free electrons in the ordinary dirac bandsmodify the nature of the plasmons.
In this study, extensive molecular dynamics simulations were carried out to investigate failure processes along different symmetric tilt grain boundaries stgb of bicrystal graphene sheet. The ruoff group, nanoscience and technology lab tmi. Philip wong and deji akinwande, cambridge university press, 2011. We report the synthesis and characterization of gete and sb2te3 phasechange nanowires via a vapor. Juan du, qingkai wang, guobao jiang, changwen xu, chujun zhao, yuanjiang xiang, yu chen, shuangchun wen, and han zhang, ytterbiumdoped fiber laser passively mode locked by fewlayer molybdenum disulfide mos2 saturable absorber functioned with evanescent field interaction, scientific report, 4, 6346 2014. China workshop on graphene and related 2d materials was held on 16. Wafer scale homogeneous bilayer graphene films by chemical. The films float on water owing to the hydrophobic nature of. Qingkai yu is currently a research assistant professor of electrical engineering and project leader in center for advanced materials. Synthesis and characterization of phasechange nanowires. Reversible multicolor chromic systems are critical for the development of advanced sensors, encryption devices, and rewritable media.