@article { ISI:000238250300028, title = {Field emission studies of novel ZnO nanostructures in high and low field regions}, journal = {Nanotechnology}, volume = {17}, number = {11}, year = {2006}, month = {JUN}, pages = {2730-2735}, publisher = {IOP PUBLISHING LTD}, address = {DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND}, abstract = {

A study of the field emission characteristics of novel structures of ZnO, namely marigolds, multipods and microbelts, has been carried out in both the close proximity configuration and the conventional field emission microscope. The use of a conventional field emission microscope overcomes the drawback of arc formation at high field values. The nonlinearity in the Fowler - Nordheim ( F - N) plot, a characteristic feature of semiconductors has been observed and explained on the basis of electron emission from both the conduction and the valence bands. The current stability exhibited by these structures is also promising for future device applications.

}, issn = {0957-4484}, doi = {10.1088/0957-4484/17/11/003}, author = {Ramgir, Niranjan S. and Late, Dattatray J. and Bhise, Ashok B. and Mulla, Imtiaz S. and More, Mahendra A. and Joag, Dilip S. and Pillai, Vijayamohanan K.} } @article { ISI:000249834900020, title = {Field emission investigations of RuO2-doped SnO2 wires}, journal = {Applied Surface Science}, volume = {253}, number = {23}, year = {2007}, month = {SEP}, pages = {9159-9163}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Field emission studies of a bunch and a single isolated RuO2:SnO2 wire have been performed. A current density of 5.73 x 10(4) A/cm(2) is drawn from the single wire emitter at an applied field of 8.46 x 10(4) V/mu m. Nonlinearity in the Fowler-Nordheim (F-N) plot has been observed and explained on the basis of electron emission from both the conduction and the valence bands of the semiconductor. The current stability recorded at the preset value of 1.5 LA is observed to be good. Overall the high emission current density, good stability and mechanically robust nature of the RuO2:SnO2 wires offer advantages as field emitters for many potential applications. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {doped semiconductor, field emission, field enhancement factor, RuO2, SnO2}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2007.05.058}, author = {Bhise, Ashok B. and Late, Dattatray J. and Ramgir, Niranjan S. and More, Mahendra A. and Mulla, Imtiaz S. and Pillai, Vijayamohanan K. and Joag, Dilip S.} } @article { ISI:000259420300006, title = {Facile synthesis and gas sensing properties of nanotriangular tin oxide}, journal = {Materials Letters}, volume = {62}, number = {28}, year = {2008}, month = {NOV}, pages = {4328-4331}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

In the present study we report a simple and convenient chemical route using pentaerythritol as a structure-directing agent for the synthesis of crystalline nanotriangular SnO2. We propose the scheme for the formation of nanotriangular structures wherein the preliminary spherical nanocrystallites are formed due to the low surface energy associated with them. These spherical nanocrystallites grow into the various linear intermediate shapes like Y, bi and tripods, which finally lead to the triangles, pyramids and bipyramids. Such variation in the structure occurs due to the structure directing pentaerythritol. These polycrystalline SnO2 nanomaterials with structural peculiarities were tested for the gas sensing characteristics. Their response towards ethanol vapor, H-2 and LPG were investigated. It was found to exhibit high response towards ethanol vapors at the operating temperature of 250 degrees C. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Nanomaterials, Oxides, Semiconductors, sensors}, issn = {0167-577X}, doi = {10.1016/j.matlet.2008.07.021}, author = {Deshmukh, Rupali G. and Badadhe, Satish S. and Vaishampayan, Mukta V. and Mulla, Imtiaz S.} } @article { ISI:000255692100010, title = {Fe-doped SnO(2) nanomaterial: a low temperature hydrogen sulfide gas sensor}, journal = {Materials Chemistry and Physics}, volume = {109}, number = {2-3}, year = {2008}, month = {JUN}, pages = {230-234}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

The effect of Fe-doping on the surface chemistry and gas-sensing properties of nanocrystalline tin oxide is analyzed. The pristine and Fe-doped SnO(2) are synthesized by the modified Pechini citrate route that produces around 40 and 18 nm sized nanoparticles, respectively. 1 at.\% Fe-doped SnO(2) shows significantly high selectivity towards hydrogen sulfide gas with capability to detect even 10 ppm of hydrogen sulfide at room temperature, with change of about one order of magnitude in the resistance within 5-15 s. In comparison, pristine SnO(2) shows negligible response towards H(2)S at room temperature. The ideal response and recovery of Fe-doped SnO(2) at low concentration of gas suggests Fe-doped SnO(2) nanomaterial as a potential low cost, low temperature H(2)S gas sensor. (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {Fe-doping, H(2)S, nanomaterial, Sensor, tin oxide}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2007.11.024}, author = {Vaishampayan, Mukta V. and Deshmukh, Rupah G. and Walke, Pravin and Mulla, Imtiaz S.} } @article { ISI:000267498700010, title = {Field emission investigation of single Fe-doped SnO2 wire}, journal = {Solid State Sciences}, volume = {11}, number = {6}, year = {2009}, month = {JUN}, pages = {1114-1117}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Tin oxide submicronwires doped with Fe element were prepared by the thermal evaporation method. Morphological and structural characterizations revealed wires with sub micron size and crystalline in nature. The field electron emission from the single Fe:SnO2 wire was carried out in conventional field emission microscope. The Fowler-Nordheim plot obtained from I-V characteristics of the wire showed a linear behavior typical that of metal. The field enhancement factor estimated from the slope of the F-N plot is 7455 cm(-1), indicating that the field emission is from nanometric features of the emitter. A current density of 10 A/cm(2) has been obtained at an applied field of 4.845 x 10(3) V/mu m. The field emission current-time record at a current level of 1 mu A for more than 3 h duration is promising for various field emissions based applications. (C) 2009 Published by Elsevier Masson SAS.

}, keywords = {Current stability, Fe doped, field emission, SnO2}, issn = {1293-2558}, doi = {10.1016/j.solidstatesciences.2009.02.011}, author = {Bhise, Ashok B. and Late, Dattatray J. and Sathe, Bhaskar R. and More, Mahendra A. and Mulla, Imtiaz S. and Pillai, Vijayamohanan K. and Joag, Dilip S.} } @article { ISI:000271238900027, title = {Field emission properties of Al-doped ZnO nanostructures}, journal = {Journal of Nano Research}, volume = {5}, year = {2009}, month = {JAN}, pages = {231-237}, publisher = {TRANS TECH PUBLICATIONS LTD}, address = {LAUBISRUTISTR 24, STAFA-ZUERICH, CH-8712, SWITZERLAND}, abstract = {

Field emission from Al-doped ZnO nanostrcutures has been investigated in planar diode configuration under ultra high vacuum conditions. The Al-doped ZnO nanostructures were synthesized by co-precipitation method with varying aluminium concentrations. The as- synthesized product was characterized by x-ray diffraction, scanning electron microscope and energy dispersive x-ray analysis. The threshold field required to draw a current density of similar to 1 mu A/cm(2) was observed to be similar to 2.0 V/mu m and similar to 2.3 V/mu m for Al-doped ZnO nanostructures synthesized with aluminium concentrations of 1\% and 3\%, respectively. The Fowler- Nordheim (F-N) plots for both the specimens exhibit non-linear behaviour, which is observed to be specimen dependent. The nonlinearity observed in the F-N plots has been interpreted on the basis of the theory of electron emission from semiconductor emitters. The field enhancement factors, estimated from the slope of the F-N plots, are found to be similar to 9.3 x 10(3) and 3.9 x 10(3) for 1\% and 3\% Al-doped ZnO emitters, respectively. The high values of the field enhancement factor Suggest that the emission is from the nanostructures. The emission current stability measured at the preset value of similar to 2 mu A over a period of more than three hours is found to be fairly stable. The results indicate use of Al-doped ZnO nanostructures as promising emitters for field emission based devices.

}, keywords = {field emission, Fowler-Nordheim plots, Nanostructures, ZnO}, issn = {1662-5250}, author = {Navale, Shalaka C. and Sheini, Farid Jamali and Patil, Sandip S. and Mulla, Imtiaz S. and Joag, Dilip S. and More, Mahendra A. and Gosavi, Suresh W.} } @article { ISI:000285413300005, title = {Fabrication of In-doped SnO2 nanowire arrays and its field emission investigations}, journal = {Journal of Experimental Nanoscience}, volume = {5}, number = {6}, year = {2010}, month = {DEC}, pages = {PII 931283663}, publisher = {TAYLOR \& FRANCIS LTD}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

The field emission of In-doped SnO2 wire array has been performed in parallel plate diode configuration. A maximum current density of 60 mu A/cm2 is drawn from the emitter at an applied field of 4 V/mu m. The nonlinearity in the Fowler-Nordheim plot, characteristics of semiconductor emitter has been observed and explained on the basis of electron emission from both the conduction and the valence bands. The current stability recorded at a preset value of 1 mu A is observed to be good. The high emission current density, good current stability and mechanically robust nature of the wires offer unprecedented advantages as promising cold cathodes for many potential applications based on field emission.

}, keywords = {cold cathodes, device, Doping, field emission, Nanowires, SnO2}, issn = {1745-8080}, doi = {10.1080/17458081003671683}, author = {Bhise, Ashok B. and Late, Dattatray J. and Sathe, B. and More, Mahendra A. and Mulla, Imtiaz S. and Pillai, Vijayamohanan K. and Joag, Dilip S.} } @article { ISI:000283453700016, title = {Fowler-nordheim plot behavior and mechanism of field electron emission from ZnO tetrapod structures }, journal = {ACS Nano}, volume = {4}, number = {10}, year = {2010}, month = {OCT}, pages = {5585-5590}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Field emission measurements of current-voltage characteristics are reported for tetrapod structures of ZnO. The nonlinear Fowler-Nordheim (FN) plot is analyzed according to a model of calculation based on saturation of conduction band current and predominance of valence band current at high-field values. The simulated FN plot exhibits similar features to those observed experimentally. The model of calculation suggests that the slope variation of the FN plot, in the high-field and low-field regions, does not depend on the magnitude of saturation. Instead, it is a characteristic of the energy band structure and voltage-to-barrier-field conversion factor of the emitting material.

}, keywords = {field emission, Fowler-Nordheim plot, Nanostructures, nonlinearity, ZnO}, issn = {1936-0851}, doi = {10.1021/nn1008403}, author = {Al-Tabbakh, Ahmed A. and More, Mahendra A. and Joag, Dilip S. and Mulla, Imtiaz S. and Pillai, Vijayamohanan K.} }