01897nas a2200193 4500008004100000022001400041245013100055210006900186260011000255300001400365490000600379520109500385100001801480700001901498700001401517700001701531700002601548856012901574 2013 eng d a2040-336400aCharge storage and electron transport properties of gold nanoparticles decorating a urethane-methacrylate comb polymer network0 aCharge storage and electron transport properties of gold nanopar aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a4404-44110 v53 a

We propose enhanced charge storage capacity of nanoparticles based polymer films. A flat band voltage window varying from 5-7 V is obtained leading to a trapped charge density of the order of 10(13) cm(-2). These results vary for two distinct morphologies obtained due to decoration of a urethane-methacrylate comb polymer (UMCP) network by gold nanoparticles (AuNPs). Films have been further investigated for morphology, optical, charge storage, and electron transport properties using techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), absorption spectroscopy (UV-Vis), scanning tunneling microscopy/spectroscopy (STM/STS) and capacitance versus voltage (C-V) measurements. SEM and AFM confirm either the deposition of AuNPs inside the UMCP network or the formation of ring like structures depending on the deposition sequence. STS measurements performed on both films are compared with bare UMCP and AuNPs films. Current versus voltage (I-V) characteristics so obtained are discussed in the light of electron transport mechanisms in such materials.

1 aPatil, Sumati1 aDatar, Suwarna1 aRekha, N.1 aAsha, S., K.1 aDharmadhikari, C., V. uhttps://library.ncl.res.in/content/charge-storage-and-electron-transport-properties-gold-nanoparticles-decorating-urethane-001699nas a2200157 4500008004100000245007200041210006900113260000800182300001000190490001100200520116500211100001801376700001901394700002201413856010601435 2017 eng d00aRevisiting HOPG superlattices: structure and conductance properties0 aRevisiting HOPG superlattices structure and conductance properti cAPR a55-600 v 658 3 aSuperlattices observed on highly oriented pyrolytic graphite (HOPG) have been studied extensively by scanning tunnelling microscopy (STM). The interest in the study of graphite superlattices has seen a resurgence since the discovery of graphene. Single layer graphene, bilayer graphene, and few layer graphene can now be grown on different substrates. The adherence of graphene to various substrates often leads to a periodic out-of-plane modulation and superlattices due to lattice mismatch. In this paper, we report STM imaging and scanning tunnelling spectroscopy (STS) of different kinds of superlattices on HOPG characterized by a variation in lattice periodicities. Our study also shows evidence of the displacement of the topmost HOPG layer by scanning different areas of the same superlattice. A correlation between the lattice periodicity with its conductance properties is derived. The results of this work are important for understanding the origin of the superlattice structure on HOPG. Investigation of such superlattices may open up possible ways to modify two dimensional electron systems to create materials with tailored electronic properties.1 aPatil, Sumati1 aKolekar, Sadhu1 aDeshpande, Aparna uhttps://library.ncl.res.in/content/revisiting-hopg-superlattices-structure-and-conductance-properties02524nas a2200253 4500008004100000022001400041245009000055210006900145260000800214300001400222490000700236520166400243653003001907653002901937653003401966653003602000100001802036700001902054700001802073700002502091700001902116700002602135856010902161 2018 eng d a1533-488000aInvestigation of disorder in mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon0 aInvestigation of disorder in mixed phase sp2sp3 bonded graphenel cAPR a2504-25120 v183 a

Disorder in a mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon (GNC) lattice has been extensively studied for its electronic and field emission properties. Morphological investigations are performed using scanning electron microscopy (SEM) which depicts microstructures comprising of atomically flat terraces (c-planes) with an abundance of edges (ab planes which are orthogonal to c-planes). Scanning tunneling microscopy (STM) is used to observe the atomic structure of basal planes whereas field emission microscopy (FEM) is found to be suitable for resolving nanotopography of edges. STM images revealed the hexagonal and non-hexagonal atomic arrangements in addition to a variety of defect structures. Scanning tunneling spectroscopy is carried out to study the effect of this short-range disorder on the local density of states. Current versus voltage (I-V) characteristics have been recorded at different defect sites and are compared with respect to the extent of the defect. As sharp edges of GNC are expected to be excellent field emitters, because of low work function and high electric field, enhancement in current is observed particularly when applied electric field is along basal planes. Therefore, it is worthwhile to investigate field emission from these samples. The FEM images show a cluster of bright spots at low voltages which later transformed into an array resembling ledges of ab-planes with increasing voltage. Reproducible I-V curves yield linear Fowler-Nordheim plots supporting field emission as the dominant mechanism of electron emission. Turn on field for 10 mu A current is estimated to be similar to 3 V/mu m.

10aField emission microscopy10aGraphene-Like Nanocarbon10aScanning tunneling microscopy10aScanning Tunneling Spectroscopy1 aPatil, Sumati1 aKolekar, Sadhu1 aKumar, Arvind1 aAlegaonkar, Prashant1 aDatar, Suwarna1 aDharmadhikari, C., V. uhttps://library.ncl.res.in/content/investigation-disorder-mixed-phase-sp2-sp3-bonded-graphene-nanocarbon01950nas a2200253 4500008004100000022001400041245010600055210006900161260000800230300002300238490000700261520108800268653001901356653001401375653002801389100002201417700001701439700002201456700001801478700002201496700001901518700002801537856013101565 2018 eng d a1022-976000aPhenazine-containing poly(phenylenevinylene): a new polymer with impressive field emission properties0 aPhenazinecontaining polyphenylenevinylene a new polymer with imp cFEB aArticle Number: 610 v253 a

Phenazine-containing poly(phenylenevinylene) (P(PHN-PV)) was synthesized using Wittig-Horner polycondensation of the appropriately designed monomers viz. 5,10-dioctyl-5,10-dihydrophenazine-2,7-dicarbaldehyde and tetraethyl ((2,5-bis((2-ethylhexyl) oxy)-1,4 phenylene) bis(methylene)) bis(phosphonate). The design embraces the specific motivation of incorporating the nitrogen-containing heterocycle viz. .phenazine in poly(phenylenevinylene) backbone. P(PHN-PV) exhibited reversible redox properties. In the field emission measurements performed on the film of P(F'HN-PV), the turn-on field was observed to be 1.93 V/mu m for the current density of 10 mu A/cm(2). The maximum current density of similar to 4.87 mA/cm(2) was achieved at the applied field of 3.84 V/mu m. The emission current showed impressive stability for 6 h at a constant current of 1 mu A (current density of about 20 mu A/cm(2)). These results emphasize the role of phenazine heterocycle with lone pair of electrons on nitrogen in lowering the oxidation onset and in turn reduction of the turn-on voltage.

10afield emission10aPhenazine10aPoly(phenylenevinylene)1 aChhatre, Shraddha1 aIchake, Amol1 aHarpale, Kashmira1 aPatil, Sumati1 aDeshpande, Aparna1 aMore, Mahendra1 aWadgaonkar, Prakash, P. uhttps://library.ncl.res.in/content/phenazine-containing-polyphenylenevinylene-new-polymer-impressive-field-emission-properties