ZnO-Nanostructures_Presentation

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ZnO-nanostructures based devices_Cortes

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ZnO-Nanostructures_Presentation

  1. 1. ZnO nanostructure ZnO-nanostructure based devices Jean P. Cortes
  2. 2. Outline What is ZnO? Wh t i Z O? Applications Nano-LEDs Principle Synthesize Optics.org/cws/article/research/26557 Proposal and applications Nano generator Nano-generator Principle Synthesize Proposal and applications Why? See Ref. [4]
  3. 3. What is ZnO? •I Inorganic compound i d • metal oxide • M lti l f Multiple forms: • semiconductor (p- and n- type) • with wide band gap gp • powder • nanostructures http://4.bp.blogspot.com/_TZ4zYEBSw1I/RjZEF1 FkGCI/AAAAAAAAA8s/- Vxz6PVYVtI/s320/nano_zinc_1.jpg • Non-toxic • Found on: • paints it • cosmetics • lotions/sunscreens http://www.zxzinc.com/UploadFiles/200 p p 71015195726571.gif
  4. 4. Applications Energy production Sensors nano-generator gas sensors Coatings bio sensors Optoelectronics wear resistance Filtering emission device (LED, (LED laser diodes) desalination non linear optical Photovoltaic devices di detector device (UV- nanostructure Solar detector)) cells ll Metrology AFM cantilever
  5. 5. Case 1 Principles of LED Diode that emits light by the movement of electrons in a semiconductor. Emission UV, visible or infrared regions. , g Unlike ordinary incandescent bulbs, they don't have a filament that will burn out and they don't get hot. = p-n Electrical junction j ti Contacts Ctt
  6. 6. Case 1 flexible Nano-LEDs by Ref. 1 Flexible Nanowire Light-Emitting Diode Polymer ZnO LED See Ref. [1] Au PS ( l t (polystyrene) ) ZnO nanowires/nanorods ITO (indium-tin-oxide) PET foil (polyethylene terephatate)
  7. 7. Case 1 Nano-LEDs synthesis See Ref. [1] (Pt) ED advantages: ITO - Electrolyte: onto 3 mM ZnCl2, 5μM AlCl3, and PET Gas 0.1 M KCl. input (O2, N2) - AlCl3 to improve T=80oC conductivity on the nanorods increase emission intensities intensities. - very good adhesion between ZnO nanowires Electrolyte and substrate substrate. ** Typical electrodeposition (ED) cell with aqueous chemical growth **
  8. 8. Case 1 Proposal - ED with aqueous chemical that will produce ZnO nanowires. - use any type of polymer carrier material (i.e. PDMS) ( ) - use the DC magnetron sputtering (for anode and cathode) - characterize fi t nanostructure and h t i first t t d See Ref. [2] then see how can we improve light. - package our device for further applications: – Low cost – Large surfaces – Industrial compatibility p y – Highly ordered vertical ZnO nanowires source Cree Inc. – Flexible and robust substrate.
  9. 9. Case 1 Applications Incandescent LED Light Fixture 5135 W Total 948 W Total source Philips source Cree Inc.
  10. 10. Case 2 Principle of Nano-generator PZ: piezoelectric effect (inside of semiconductors such as p ( ZnO) is the ability of a crystalline structure to generate an electrical current with applied stress and backwards. Mechanical energy Vibrational energy Chemical energy (glucose) hydraulic energy = Direct Current http://www.school-for- p champions.com/science/images/static_c auses-piezoelectric.gif
  11. 11. Case 2 Nano-generator by Ref. 3. Schematic of the interacting between AFM tip with ZnO nanowires. See ref [4] Nanowires The pioneer Dr. Zhong Lin Wang A prototype direct‐current  nanogenerator was developed by Georgia Tech researchers using an array of zinc oxide nanowires. See Ref. [3] Nanobelts ZnO NW / NB Pros: - Simple / Cost Efficient / Non-toxic - C b subjected to extremely l Can be bj d l large elastic d f l i deformation without i ih deformation or fracture - Can be bent with little force - Small diameter free of dislocation higher resistant of fatigue
  12. 12. Case 2 Proposal (I) Thermal Evaporation -V Vapor S lid (VS) Solid Nanobelts N b lt 1. Small tube furnace low cost 2. Zn atoms evaporate from Zn powder under a heating process 3. Zn + 02 ZnO vapor deposited on the walls of the quartz tube 4. No catalyst needed - Fabrication Techniques = f (T and Distance) http://nano.materials.drexel.edu/Facilities/FacilitiesImage/TubeFurnace.jpg
  13. 13. Case 2 Proposal (II) Metal-Organic Chemical Vapor Deposition (MOCVD) – uses a metal-organic gas source (Zn precursor Zn(C2H5)2 or (CH3)2Zn-N(CH2CH3)3), O source = N2O) – Precursor is heated to its gas phase – Carried to a heated substrate by a carrier gas – react with the substrate to deposit the solid product ZnO nanowires Why preferred? – High purity RF Micro Devices of Charlotte. The machine is a custom-built flow – Large area growth modulation epitaxial (FME) metal organic chemical vapor deposition (MOCVD) reactort – Control of film thickness – High growth rates – Preferred structural orientation
  14. 14. Case 2 Applications Power to biomedical detection and monitoring g devices Portable Electronics Long Term applications Alternative Energy Applications
  15. 15. Why ZnO nanowires? Case 1. Nano-LEDs 160 lumens/W. - reduce the amount/consumption of electricity compared with incandescent lights (20 lumens/W). - l CO2 and di ti l li ht emission. less d directional light ii - device stability - ultra-low current / voltage / power operation - reliability and long lifetime - maintance avoidance - rugged Case 2. Nano-generator - convenient/portable alternative to battery packs - Provides power to nanodevices - Portable electronics - Implantable medical devices - Biosensors
  16. 16. References Case 1. 1. Nadarajah Athavan, Robert Word, and Jan Meiss. quot;Flexible inorganic nanowire Light- Emitting diode.quot; Nano Letters 8.2 (2008): 534-537. 2. Park, S.-H, Kim S.-H, and Han S.-W. quot;Structural Properties of Nitrogen-Ion implanted ZnO Nanorods.quot; k Z ON d quot; korean Ph i l S i t 50 (2007) 1557-156. Physical Society (2007): 1557 156 Case 2. 3. 3 Wang, Wang Zhong Lin quot;Piezoelectric Nanostructures: From Growth Phenomena to Electric Lin. Piezoelectric Nanogenerators.quot; MRS Bulletin 32 (2007): 109-116. 4. Wang, Xudong, Jinhui Song, Jin Liu, and Zhong Wang. quot;Direct-Current Nanogenerator Driven by Ultrasonic Waves.quot; Science 316.5821 (2007): 102-105. 5. 5 Cheng , S J G R Whang and Y.C. Liu. quot;the structure and photoluminescense S.J., G.R. Whang, Y C Liu properties of ZnO nanobelts prepared by thermal evaporation.quot; Journal of Luminescense 129 (2008): 340-343. 6. Li, J. Y., Q. Zhang, et al. (2009). quot;Diameter-Controlled Vapor-Solid Epitaxial Growth and Properties of Aligned ZnO Nanowire Arrays quot; Journal of Physical Chemistry C 113(10): Arrays. 3950-3954. 7. Wang, Z. L. (2008). quot;Towards Self-Powered Nanosystems: From Nanogenerators to Nanopiezotronics.quot; Advanced Functional Materials 18(22): 3553-3567.
  17. 17. That’s ll F lk ! Th t’ all Folks!

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