8. Nanotechnology – some examples Photo by David Hawxhurst-Woodrow Wilson International Center for Scholars
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10. Nano products – Health & Fitness Category Data courtesy Wilson of Woodrow International Centre for Scholars
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14. Nanocomposites for Photovoltaic Energy Harvesting and Storage Gehan A. J. Amaratunga Electrical Engineering Division, Engineering Dept, University of Cambridge Cambridge UK ePEC Electronics, Power & Energy Conversion
18. Alternative cell technologies which are ‘cheaper’ not required for growth of solar power generation. A new Si industry growing rapidly with massive investment in new capacity
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22. MWCNT NEMS Switch: Gate voltage applied to deflect suspended CNT to make contact with source. source drain gate Example of Category 1 Research at Cambridge: S.N. Cha et al, APL 2005
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26. Zinc Oxide Nanowire Growth (CVD) ZnO (s) + C (s) Zn (gas) + CO (gas) Hongjin Fan et al. Nanotechnology 17 (2006) Silicon Sapphire
27. Zinc Oxide Nanowire Characterization 2.58 Å < 001 > 01-10 0002 CNT@Cambridge Group http://www-g.eng.cam.ac.uk/cnt/
32. SWNT Thin Films with ZnO NWs ZnO Nanowires SWNT TF Parekh, Fanchini, Eda, Chhowalla APL 90 (2007) SWNT Network
33. ZnO NW - SWNT TF OPVs 100 mW/cm 2 Unalan et al. to be submitted Substrate
34. Use of nanostructured electrodes to have ‘area’ concentrator cells. For fixed material, target is large h but small d, l Cell 1: interpenetrated junction Cell 2: interpenetrated electrodes
35. Vertically aligned CNT – a-Si:H cell CNT a-Si:H (n-i) ITO W Fig 2. A schematic diagram showing the periodic CNT arrays offer multiple absorption opportunities in amorphous silicon photovoltaic cell.
36. a-Si:H on CNT cell Periodic CNT array a-Si: H and ITO coated CNT array
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38. Fabrication sequence for CNT/a-Si:H/ITO cell I Deterministic MWCNT growth II Conformal n+ and i-a-Si:H III – ITO transparent contact IV Completed array (hole collector)
39. 500 nm MWCNT a-Si:H ITO Capacitance enhancement (i) with CNT (ii) no CNT 40 nm TEM and EDX
40. Performance of photovoltaic devices with and without CNTs arrays when illuminated with normal incident light. (b) Performance of solar cell with dot pattern CNTs electrode when illuminated with light from different incident angles
46. A room temperature processed solar cell on flexible substrate A novel ionic liquid was synthesized by grafting polyvinyl alcohol (PVA) with ionic liquid 1-butyl-3-vinylimidazolium bromide (VIC4Br) under the irradiation of a 60Co- γ source.
51. LED Fabrication Step 1: Hydrothermal Growth of ZnO nanowires on ITO coated glass Step 2: Spin coat insulating layer, dry and etch the tips No plasma 1 min 3 min 6min
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53. LED structure Step 1: Hydrothermal Growth of ZnO nanowires on ITO coated glass Step 2: Spin coat insulating layer, dry and etch the tips Step 3: Spin coat organic p-type layer Step 4: Evaporate metal contact
64. Li ion BATTERY TECHNOLOGY TRENDS ENERGY SOURCES New Lithium-based chemistries provide potential for further battery capacity improvement. A major limitation of Li ion batteries remains their loss of capacity with time irrespective of the number of charge-discharge cycles. A capacity loss of 20% per year is common.
65. A Practical solution would be an integrated device in which it appears as if a Li ion battery is connected in parallel with a supercapacitor + + - -
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68. New method for bulk production of nanocarbon materials which can be suitable for energy storage applications Nature, 506 (414), 2001 Nano-onions
69. Carbon nanohorns : Bulk synthesis by arc in liquid nitrogen. Enhanced take up of metal/catalyst particles. Suitable for both Li-ion anode and Pt catalyst on electrode for fuel cells Nanotech.546(15)2004
71. CNH On graphite ELECTRONICS, POWER AND ENERGY CONVERSION GROUP
72. NP agglomerates are 20-100nm diameter spherical structures with concave and convex curves inside the structure. Distance between the graphene sheets, d=0.376nm compared to ordinary graphite 0.336nm. Chemical and surface energy differences are expected because of the highly curved surface structures, and possible edge formations at the surface ELECTRONICS, POWER AND ENERGY CONVERSION GROUP
73. Surface Area Measurements of SWNHs Nitrogen adsorption isotherms taken at 77K for as-produced and modified SWNH (oxidized in air at 350 ºC). 1000 ~1500 m 2 /g ELECTRONICS, POWER AND ENERGY CONVERSION GROUP
74. Controlled MWCNT growth as basis for Supercapacitor electrodes grown single multi-wall carbon nanotube Catalyst shape Number of MWCNT Process is very simple High Integration density ; vertical structure Various applications Structure effect Function part Nano capacitor Nano switch <200nm K B K Teo et al, Nanotechnology 14, 2003
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77. - Electrical characteristics measurement Structure I –point MWCNTs 1um 1um Structure II-line MWCNTs 1um Ni catalyst was patterned in a dot shape (<180nm, diameter) with 1 m pitch over a 200um x 200um area. Top electrode : 220um x 320um Ni catalyst was patterned in a line shape with 180nm width, 200um length, and 1 m pitch over a distance of 200 m Top electrode : 220um x 320um
78. Capacitance Leakage current -The capacitance of the dot pattern and line pattern are about two and six times higher respectively compared to an equivalent MIM structure in same area. -This is mainly due to an increase in the effective electrode area by incorporation of vertical MWCNTs. - One MICNM structure is about 1 fF -The leakage current density is a little bit higher than in the standard MIM structure, however, this is still acceptable for many applications