Carbon nanostructure based electrodes for high efficiency dye sensitized solar cell

Synthesis and functionalization of large-area graphene and its structural, electrical and electrochemical properties has been investigated. First, the graphene films, grown by thermal chemical vapor deposition (CVD), contain three to five atomic layers of graphene, as confirmed by Raman spectroscopy and high-resolution transmission electron microscopy. Furthermore, the graphene film is treated with CF4 reactive-ion plasma to dope fluorine ions into graphene lattice as confirmed by X-ray photoelectron spectroscopy (XPS) and UV-photoemission spectroscopy (UPS). Electrochemical characterization reveals that the catalytic activity of graphene for iodine reduction enhanced with increasing plasma treatment time, which is attributed to increase in catalytic sites of graphene for charge transfer. The fluorinated graphene is characterized as a counter-electrode (CE) in a dye-sensitized solar cell (DSSC) which shows ~ 2.56% photon to electron conversion efficiency with ~11 mAcm−2 current density. Second, the large scale graphene film is covalently functionalized with HNO3 for high efficiency electro-catalytic electrode for DSSC. The XPS and UPS confirm the covalent attachment of C-OH, C(O)OH and NO3- moieties with carbon atoms through sp2-sp3 hybridization and Fermi level shift of graphene occurs under different doping concentrations, respectively. Finally, CoS-implanted graphene (G-CoS) film was prepared using CVD followed by SILAR method. The G-CoS electro-catalytic electrodes are characterized in a DSSC CE and is found to be highly electro-catalytic towards iodine reduction with low charge transfer resistance (Rct ~5.05 Ωcm 2) and high exchange current density (J0~2.50 mAcm -2). The improved performance compared to the pristine graphene is attributed to the increased number of active catalytic sites of G-CoS and highly conducting path of graphene. We also studied the synthesis and characterization of graphene-carbon nanotube (CNT) hybrid film consisting of graphene supported by vertical CNTs on a Si substrate. The hybrid film is inverted and transferred to flexible substrates for its application in flexible electronics, demonstrating a distinguishable variation of electrical conductivity for both tension and compression. Furthermore, both turn-on field and total emission current was found to depend strongly on the bending radius of the film and were found to vary in ranges of 0.8 - 3.1 V/μm and 4.2 - 0.4 mA, respectively.

Ninth Conference on Cuban and Cuban-American Studies "Dispersed Peoples: The Cuban and Other Diasporas"

This flyer promotes the Ninth Conference on Cuban and Cuban-American Studies "Dispersed Peoples: The Cuban and Other Diasporas" , cosponsored by FlU's Cuban Research Institute, FlU African and African Diaspora Studies Program, Center for the Humanities in an Urban Environment, Exile Studies Program, and WPBT2. This event was held May 23, 2013 - May 25, 2013.

A Dispersed People: Social and Cultural Dimensions of the Cuban Diaspora, Book Presentation with Volume Editor Jorge Duany

This flyer promotes the event "A Dispersed People: Social and Cultural Dimensions of the Cuban Diaspora, Book Presentation with Volume Editor Jorge Duany, comments by Lillian Manzor" sponsored by the School of International and Public Affairs at Florida International University. This event was held at Books and Books in Coral Gables.

9th Conference on Cuban and Cuban-American Studies, Dispersed Peoples: The Cuban and Other Diasporas [Call for Papers and Panels]

This is the call for papers and panels for the 9th Conference on Cuban and Cuban-American Studies, Dispersed Peoples: The Cuban and Other Diasporas.