The Atlanta Area Chemical Physics (AACP) seminar series presents Prof. Anvar Zakhidov, Department of Physics, University of Texas, Dallas.

Transparent Carbon Nanotube Sheets for Solar cells, OLEDs and Other Nanostructured Devices

We have recently developed a method to create oriented free standing and optically transparent multiwall carbon nanotube (T-CNT) sheets [1], which are chemically stable, mechanically strong and have a combination of other interesting properties. It is demonstrated, that T-CNT films can be laminated on any flexible substrates, starting from free standing aerogel T-CNT sheets, obtained by dry drawing self-assembly from a CNT-forest [1], and densified to thicknesses of 50-100 nm. In the talk we will describe how this CNT sheets can be used as interfacial electrode for charge collection in two types of solar cells (SC): organic photovoltaic cells (OPV) and dye sensitized cells (DSC). This T-CNT films have been also used as charge injectors, instead of conventional ITO coatings in two types of organic LEDs: both in polymeric PLEDS and low molecular OLEDs. Such a film, with initial sheet resistance of 500 ohm/sq, should be first coated by optimal layers of PEDOT-PSS for its planarization and further used as charge collecting/ injecting porous three-dimensional network. To increase the conductivity and electrochemical activity of such a novel transparent anode the T-CNT sheets are coated with highly conductive single wall tubes (SWCNT) from various ink- solutions and also by vacuum deposited metals. We show that the transparent sheets of SWCNT/MWCNT perform as a flexible anode for polymeric bulk heterojunction solar cells (SC) combined with DSCs. Nanocomposite T-CNT sheets also can be used in tandems of polymeric and dye sensitized solar cells as transparent charge recombination or interconnect layers. The newest data on CNT sheets as hole injectors in OLEDs with polymers (MEH-PPV) combined with quantum dots (QD) will be also presented and discussed.

[1] M. Zhang, S. Fang, A. Zakhidov, S. B. Lee, A. Aliev, R.H. Baughman, Science, 309,(2005) 1215.

For more information contact Dr. Christine Payne (404-385-3125).