Title :

Photovoltaic Solar Cells: Bottlenecks and Our Approaches

Speaker :

Prof. Meng Tao

Department of Electrical Engineering

University of Texas at Arlington, USA

Venue :

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

Date :

Mar 26, 2010, Friday
2:00 PM - 3:00 PM

Abstract :

This presentation will be divided into three parts. Part one will provide an overview on solar cell technologies. In particular, natural resource limitations to terawatt-scale deployment of first-generation wafer-silicon and second-generation thin-film solar cells will be outlined, from which a comprehensive approach can be formulated to make solar electricity a significant source of energy in our society. Part two will showcase our approach to post-silicon terawatt-scale solar cells, i.e. solution fabrication of three-dimensional metal chalcogenide solar cells. These chalcogenides are earthly-abundant, low-cost, energy-efficient and non-toxic. Major technical challenges in utilizing chalcogenides for next-generation solar cells will be outlined, along with our progress in meeting these challenges including 1) record-low resistivity for chemically-deposited zinc oxide as a transparent conducting oxide and 2) a solution-deposited, omnidirectional and universal surface texture for antireflection in solar cells. Part three will summarize our work on terawatt-scale wafer-silicon solar cells, especially on valence-mending passivation to eliminate surface states, which are an inherent feature of a semiconductor surface since the Bardeen era. By depositing a monolayer of sulfur or selenium on the silicon (100) surface, we have demonstrated record-high and record-low Schottky barriers. The record Schottky barriers led to low-resistance ohmic contacts and enable silicon electronics in solar inverters with operation temperature above 300°C. Another important application is valence-mending passivation of grain boundaries in poly-silicon solar cells.

Biography :

Dr. Meng Tao is a Professor of Electrical Engineering at the University of Texas at Arlington. His career started in the early 1980’s when he worked on amorphous silicon deposition as a graduate student at Zhejiang University. He spent the next nine years with the State Key Lab for Silicon Materials in Hangzhou, China. He received his Ph.D. in Materials Science and Engineering from the University of Illinois at Urbana-Champaign in 1998 and has been on the faculty at UTA since 2001. His current research focuses on defect passivation on semiconductor surfaces and in bulk semiconductors, solution fabrication of three-dimensional inorganic solar cells, predictive modeling of chemical vapor deposition and electrochemical routes to solar-grade silicon. He has received a number of awards and recognitions, including the South Central Bell Professorship in 2001, Outstanding Young Faculty Award in 2004 and Research Excellence Awards from 2005 through 2009.

    **************************************** 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.