Associate Professor Daniel Macdonald
Australian National University, Australia

Silicon solar cell operation and the impact of impurities

Abstract

This tutorial will review the impact of impurities and defects on the performance of crystalline silicon solar cells. These include metals such as Fe and Cr, oxygen-related defects such as the important boron-oxygen complex, and crystal defects such as dislocations and grain boundaries. The orgins of these defects and impurities will be discussed, as well as strategies for reducing their impact, such as gettering and hydrogenation. The talk will also examine the relative impact of the most important of these defects in both p- and n-type silicon, which exhibit some fundamental differences. Finally, the potential use of low-cost, but low-purity, solar-grade silicon feedstocks will be discussed in the context of impurities, in particular in relation to the impact of dopant compensation.

Since completing his PhD at The Australian National University (ANU) in 2001, Dr Macdonald has worked as a Research Scientist at the Energy research Centre of the Netherlands (ECN) in 2003, and at the ANU where he has held two Australian Research Council fellowships. His research interests are in the field of crystalline silicon solar cells, in particular the following aspects: the characterisation, detection and reduction of defects and impurities in silicon solar cells; recombination and trapping in silicon; n-type silicon solar cells; and low-cost solar-grade silicon.