Date of Graduation

Fall 2009

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Kartik Ghosh

Keywords

carbon nanotubes, solar cell, photoactive particles, photocurrent, illumination

Subject Categories

Materials Science and Engineering

Abstract

In this work, I used three different methods to fabricate solar cell structures on an indium tin oxide substrate. For the first method, a multi-layered structure was prepared by using carbon nanotubes (CNTs) and tin oxide (SnO2). First, a single walled carbon nanotube (SWCNT) layer was deposited on the ITO substrate, and then the photoactive material was coated on the top of the SWCNT layer. For the second method, photoactive particles were added to a solution of SWCNTs. The SWCNTs/SnO2 solution was mechanically stirred and then deposited on the ITO substrate. For the third method, photoactive particles were synthesized on CNTs through a chemical-solution routine using SnCl4 as a precursor. I characterized the morphology and structure of the CNTs coated with SnO2 nanoparticles prepared with the three different methods by using a field emission scanning electron microscope (FESEM) equipped with an X-ray energy dispersive spectrometer (EDS). Photo-electrochemical properties of all electrodes were characterized the by using an electrochemical station; mainly, I examined the photocurrent generated under periodic illumination. Results indicate that there are significant differences in the photocurrent in the presence of CNTs. The following hypothetical mechanism could be possible: 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.

Copyright

© Baleeswaraiah Muchharla

Campus Only

Share

COinS