Photoelectrochemical properties of carbon nanotube/SnO2 nanostructures prepared by three different methods
In this work, we employed three different methods to fabricate solar cell structures on indium tin oxide (ITO) substrates. For the first method, multi-layered structures were prepared by using single walled carbon nanotubes (SWCNTs) and tin oxide (SnO2). First, a SWCNT layer was deposited on the ITO substrate; and photoactive material was then coated on the top of the SWCNT layer. For the second method, photoactive particles were added to a solution of SWCNTs. The SWCNT/SnO2 solution was mechanically stirred and then deposited on the ITO substrate. For the third method, we synthesized photoactive particles on SWCNTs through a chemical-solution routine using SnCl4 as a precursor. We characterized the morphology and structure of the SWCNTs coated with SnO2 nanoparticles prepared with the three different methods by using a field emission scanning electron microscope equipped with an X-ray energy dispersive spectrometer. We characterized the photoelectrochemical properties of all electrodes by using an electrochemical station; mainly, we examined the photocurrent generated under periodic illumination. Our results indicate that there are significant differences in the photocurrent in the presence of SWCNTs. We propose the following hypothetical mechanism: without carbon nanotubes, generated electrons (when light is absorbed by SnO2 particles) must cross the particle network to reach an electrode. Many electrons never escape this network to generate an electrical current. The carbon nanotubes "collect" the electrons and provide, therefore, a more direct route to the electrode, thus improving the efficiency of the solar cells.
Physics, Astronomy, and Materials Science
Muchharla, Baleeswaraiah, and Lifeng Dong. "Photoelectrochemical Properties of Carbon Nanotube/SnO 2 Nanostructures Prepared by Three Different Methods." MRS Online Proceedings Library Archive 1204 (2009).
Materials Research Society Symposium Proceedings