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SUMMARY:Effect of carbon modification on the electrical\, structural and o
 ptical properties of TiO2 electrodes and their performance in lab-scale dy
 e sensitized solar cells
DTSTART;VALUE=DATE-TIME:20110714T150000Z
DTEND;VALUE=DATE-TIME:20110714T170000Z
DTSTAMP;VALUE=DATE-TIME:20260711T212729Z
UID:indico-contribution-5020@events.saip.org.za
DESCRIPTION:Speakers: Raymond Taziwa (University of Fort hare)\nCarbon mod
 ified titanium dioxide nanoparticles (C:TiO2 NPs) have been synthesized by
  ultrasonic nebulizer spray pyrolysis (USP) and pneumatic spray pyrolysis 
 (PSP) techniques using titanium tetraethoxide as the precursor solution. H
 igh resolution transmission electron microscopy on the NPs shows differenc
 e in lattice spacing in the NP structures prepared by the two methods – 
 2.02 Å for the USP NPs and an average of 3.74 Å for the PSP NPs. The mos
 t probable particle sizes are 3.11 nm and 5.5 nm respectively. The carbon 
 doping only changes the lattice spacings of the TiO2 lattice\; the most pr
 edominant plane is the (101) in TiO2 reciprocal lattice as determined from
  the fast Fourier transform of most of the particle images. Raman spectros
 copy supported by FTIR confirms the TiO2 polymorph to be anatase with the 
 intense phonon frequency at 153 cm-1 blue-shifted from 141 cm-1 due to bot
 h carbon doping and particle size.  A modified phonon confinement model fo
 r nanoparticles has been used to extract phonon dispersion and other param
 eters for anatase for the first time. Electronic measurements show “nega
 tive conductance” at some critical bias voltage\, which is characteristi
 c of n-type conductivity in the carbon doped TiO2 NPs as confirmed by the 
 calculated areas under the I-V curves. This is a necessary material proper
 ty for the Grätzel type of solar cells application. Practical solar cells
  built from carbon doped TiO2 electrodes show up to 5 times improvement in
  efficiency compared to pure TiO2 electrodes of similar construction.\n\nh
 ttps://events.saip.org.za/event/7/contributions/5020/
LOCATION: Asteria
URL:https://events.saip.org.za/event/7/contributions/5020/
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