02320nas a2200313   4500008004100000022001400041245011600055210006900171260000800240300001100248490000600259520127500265100002401540700002001564700002501584700001901609700002801628700002401656700001801680700001701698700002801715700001901743700002301762700002301785700002301808700002201831700002401853856012901877       2018                        eng d  a2158-322600aHigh-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures0 aHighperformance field emission device utilizing vertically align  cJAN  a0151170 v83 a<p>The vertical aligned carbon nanotubes (CNTs)-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si) wafer substrate at 775 degrees C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness) as a barrier layer and iron (Fe, 1.5 nm thickness) as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2-30 walls with an inner diameter of 3-8 nm. Raman spectrum analysis shows G-band at 1580 cm(-1) and D-band at 1340 cm(-1). The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm(2) at 1.2V/mu m), low turn-on field (0.6 V/mu m) and field enhancement factor (6917) with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources. (c) 2018 Author(s).</p>1 aGupta, Bipin, Kumar1 aKedawat, Garima1 aGangwar, Amit, Kumar1 aNagpal, Kanika1 aKashyap, Pradeep, Kumar1 aSrivastava, Shubhda1 aSingh, Satbir1 aKumar, Pawan1 aSuryawanshi, Sachin, R.1 aSeo, Deok, Min1 aTripathi, Prashant1 aMore, Mahendra, A.1 aSrivastava, O., N.1 aHahm, Myung, Gwan1 aLate, Dattatray, J.  uhttp://library.ncl.res.in/content/high-performance-field-emission-device-utilizing-vertically-aligned-carbon-nanotubes-based02850nas a2200253   4500008004100000022001400041245010500055210006900160260000800229300001100237490000600248520197200254653002102226653001902247653004502266653001602311100002302327700002402350700002502374700002302399700002402422700002802446856012202474       2019                        eng d  a2053-159100aGraphene nanosheets assisted carbon hollow cylinder for high-performance field emission applications0 aGraphene nanosheets assisted carbon hollow cylinder for highperf  cSEP  a0950660 v63 a<p>Electron sources are critical constituents for myriad many electronic applications including electron imaging, mass spectroscopy etc. Here, we report the realization of high-performance field emission from graphene assisted carbon hollow cylinders (Gr-CHCs) composed of multi-stacked radially aligned CNTs. These CHCs have built-in synthesis related Fe nanoparticles (NPs). This engineered nano-structure exhibits excellent field emission properties such as one of the ultra-low turn-on field (0.64V mu m(-1) at 10 mu A cm(-2)), low threshold field (0.74V mu m(-1) at 100 mu A cm(-2)), very high current density (15.49 mA cm(-2) at 1.32V mu m(-1)) which is nearly double the current density obtained in our previous study. High field enhancement factor (0.72. x. 10(4)) with highly stable emission current at 100 mu A was observed for more than 3 hrs at the base pressure of similar to 1. x. 10(-8) mbar. This study suggests an approach to enhance the current density using the proposed innovative nanostructure and forms the basic theme of this communication. Highly efficient and stable field emissions observed are attributed to the geometry of cylinder and the production of the high density of sharp protrusions within the graphene sheets which enhance the local electric field and dramatically enhance field emission. This innovative cylindrical geometry associated with graphene assisted on Fe bearing aligned CNTs along with the periphery of the bulk cylinder provides an easy injection of electrons from the conduction band of CHCs into the vacuum in the presence of an external electric field. The tunability of field emission properties of these CHCs can be easily achieved by tailoring their diameter (10 and 20 mm) and different concentrations of the precursor. This new approach of the graphene assisted cylindrical geometry-based field emitter source provides enormous prospects and demand for next-generation high resolutions display devices.</p>
10aCarbon nanotubes10afield emission10agraphene assisted carbon hollow cylinder10aprotrusions1 aTripathi, Prashant1 aGupta, Bipin, Kumar1 aBankar, Prashant, K.1 aMore, Mahendra, A.1 aLate, Dattatray, J.1 aSrivastava, Onkar, Nath  uhttp://library.ncl.res.in/content/graphene-nanosheets-assisted-carbon-hollow-cylinder-high-performance-field-emission