Title :

Nanostructured Optoelectronics: New Device Concepts for Improved Efficiency and Widespread Utilization

Speaker :

Dr. Ni Zhao

Postdoctoral Research Associate, Organic and Nanostructured Electronics Laboratory

Massachusetts Institute of Technology, USA

Venue :

Room 215, William M. W. Mong Engineering Building, CUHK

Date :

Apr 19, 2010, Monday
2:00 PM - 3:00 PM

Abstract :

Over the past several decades, intensive research efforts have been undertaken to develop optoelectronic devices through the use of nanostructured materials including small molecules, conjugated polymers, and colloidal nanocrystal quantum dots. Unlike conventional semiconductors such as Si and GaAs, nanostructured materials are compatible with low-cost, large area, roll-to-roll processing. This translates into lower energy intensity for material processing. In addition, nanostructuring of solids enables tunability over electronic and optical properties. In this talk, I will discuss design, fabrication, and characterization of solar cells and field-effect transistors based on nanostructured materials.

First, I will address some of the key issues for realizing nanostructured solar cells. As an example, I will describe a bilayered organic/quantum dot hybrid solar cell that is able to harvest a broad spectral range of solar radiation, and at the same time exhibits excellent performance characteristics. Following presentation of experimental results, I will explain the operation mechanism of the hybrid solar cell. Second, I will discuss studies on another type of nanostructured material, conjugated polymers, using a field-effect transistor structure. Specifically, the relationship between the processing of the polymer, its morphology, and the resulting charge transport properties will be described. Finally, I will demonstrate fabrication of nanostructured electronics using a novel inkjet printing technique.

Biography :

Dr. Ni Zhao received her Ph.D. degree in 2008 from the University of Cambridge, UK, and she is presently a postdoctoral research associate at Massachusetts Institute of Technology (MIT), USA. Her current work focuses on developing novel hybrid solar cell structures which incorporate colloidal nanocrystal quantum dots with organic and inorganic materials, and using these structures to study electronic processes in solar cells.

    **************************************** ALL ARE WELCOME ****************************************

Enquiries: Ms. Winnie Wong or Prof. Wen J. Li, Department of Mechanical and Automation Engineering, CUHK at 2609 8337. *MAE Series (2009-10) is contained in the World-Wide Web home page at http://www3.mae.cuhk.edu.hk/maeseminars.php#mae