Electron transfer dynamics from organic dyes to semiconductor nanocrystalline films

PHYS 374

Dave Stockwell, dstockw@emory.edu, Jier Huang, jhuang8@emory.edu, Abdelaziz Boulesbaa, aboules@emory.edu, Zhe Zhang, zzhan23@emory.edu, and Tianquan Lian, tlian@emory.edu. Department of Chemistry, Emory University, 1515 Dickey Dr, Atlanta, GA 30322
Electron transfer dynamics in dye-sensitized nanocrystalline semiconductor films are of intense interest, due to the potential application in fabrication of low-cost light harvesting devices and molecular electronics. Interfacial electron transfer (ET) dynamics from organic dyes (xanthene, coumarin, and stylene derivatives) to different semiconductors (TiO2, SnO2, In2O3, ZnO) were investigated using both ultrafast IR and visible transient absorption spectroscopy. The IR injection dynamics to the different semiconductors were directly correlated with visible absorption dynamics of the sensitizer cation and the excited state quenching due to injection. The direct detection of electrons in the semiconductor films with ultrafast IR spectroscopy after excitation of the sensitizers showed an injection rate dependence on the different semiconductors, where TiO2>SnO2~In2O3>ZnO. These results are compared to other dye-sensitizer systems that have already been extensively investigated. Injection dynamics between these semiconductor systems will be discussed, as well as a potential model for the observed results.
 

PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008