Lecture Title:Visible light emission from silicon-based thin film nanostructures

Peter Mascher

Fellow, Canadian Academy of Engineering

Department of Engineering Physics and Centre for Emerging Device Technologies

McMaster University, Hamilton, Ontario Canada L8S 4K1

Abstract:

The possible application of luminescent Si-based materials for solid-state lighting (SSL) has emerged as an interesting area of research as it would offer substantial advantages in terms of cost and manufacturability. In order for Si-based materials to be used in SSL schemes it is necessary to have precise control of the emission from these materials. This can be accomplished through the use of rare earth dopants such as Ce, Tb, and Eu to obtain precise blue, green, and red emissions, respectively. Details of the luminescence mechanisms in these materials, however, remain a matter of debate, particularly in cases where the composition of the host matrix is varied and/or where nanoclusters/nanocrystals form during the anneal process. Nano-structured silicon shows quantum confinement effects that contribute strongly to the luminescence.

After a brief review of the latest developments in the field, this talk will focus on the luminescence of rare earth (Ce,Tb,Eu) doped silicon oxides, nitrides, and carbides. We have demonstrated very high, optically active concentrations of the rare earths by using in-situ doping processes, using electron cyclotron resonance chemical vapour deposition (ECR-CVD) or inductively coupled plasma (ICP) CVD as low thermal budget processes for film deposition. I will describe the salient features of the deposition systems and relate important process parameters to the observed luminescence.

Finally, I will discuss some of the challenges in developing electrically driven lighting cells suitable for SSL and in particular, the development of white light emitters from rare earth doped Si-based materials.

Biography:

Peter Mascher obtained a PhD in Engineering Physics in 1984 from the Graz University of Technology (TUG) in Austria and spent about four years as a post-doctoral fellow and research associate at the University of Winnipeg. He joined McMaster University in 1989 in a position initially funded by the Ontario Centre for Materials Research. He is a professional engineer and a professor in the Department of Engineering Physics, was Chair of the Department from 1995 to 2001, and from 2003 to 2014 served as the Associate Dean (Research and External Relations) of the Faculty of Engineering, with responsibilities for coordinating major research initiatives and collaborations of the Faculty. After serving as Acting Associate Vice-President, International Affairs from 2012 to 2013, Dr. Mascher since February 2014 is overseeing McMaster’s International Portfolio as Associate Vice-President, International Affairs.

Dr. Mascher holds the William Sinclair Chair in Optoelectronics and leads active research groups involved in the fabrication and characterization of thin films for optoelectronic applications, the development and application of silicon-based nanostructures, and the characterization of defects in solids by positron annihilation spectroscopy. His research work is funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation of Innovation (CFI), several federal and provincial Centres of Excellence, and industry. Since 2010, he leads a collaborative initiative to transform the McMaster Nuclear Reactor into one of the world’s brightest positron sources for applied and fundamental research. Dr. Mascher has supervised about 60 Ph.D. and master’s degree students, has authored or coauthored close to 250 publications in refereed journals and conference proceedings, and has presented many invited lectures at international conferences and workshops. In 2012, he was inducted as a Fellow of the Canadian Academy of Engineering.

Dr. Mascher is a member of the Steering Committee of the bi-annual Canadian Semiconductor Science and Technology Conference (CSSTC), of the executive body of the Dielectric Sciences and Technology Division of the Electrochemical Society and chair of the International Advisory Committee on Positron Annihilation. From 2003 to 2007 he served as the Program Director of the Ontario Photonics Consortium. He currently is a member of the governing body of organizations as diverse as the Green Auto Power Train Initiative, the Network for the Engineering of Complex Software-Intensive Systems for Automotive Systems, and the Dielectric Science and Technology Division of the Electrochemical Society and serves as the Vice-Chair of Nano Ontario.