Principal Investigator Gernot Heiser Project g32

School of Computer Science and Engineering, Machine VP

University of New South Wales

Co-Investigators Alistair Sproul, Christiana Honsberg and Sean Edmiston

Centre for Photovoltaic Devices & Systems, University of New South Wales

Simulation of Silicon Solar Cells

This project uses two-dimensional numerical modelling to study the internal operations of the novel multilayer thin film solar cells which are presently being developed at the Centre for Photovoltaic Devices & Systems, UNSW. These cells are to produce energy at competitive prices, and are therefore manufactured from inexpensive, low quality material.

What are the basic questions addressed?

The main purpose of this project is to study the effects of material defects on solar cell performance, and to help derive design rules which will result in reasonably efficient cells.

What are the results to date and the future of the work?

The work performed so far has confirmed that the effects of material defects on the performance of these cells is much smaller than it would be with conventional designs. However, these results have, so far, mostly qualitative character and much more work is required until appropriate design rules can be stated.

What computational techniques are used and why is a supercomputer required?

The simulations solve a coupled system of non-linear partial differential equations by the "finite volume" method. The systems of linear equations resulting from discretisation and linearisation are generally extremely ill-conditioned, which makes them impossible to solve by iterative methods and lead to convergence problems even with direct solvers. We typically use about 20,000 to 40,000 grid points and require in excess of 200MB RAM, more than is normally available on workstation kind of machines. On workstations with about 100MB memory typical run times for one simulation are in excess of 24h.

Publications

Capitalizing on two dimensional minority carrier injection in silicon solar cell design, C B Honsberg, S Edmiston, L Koschier, S R Wenham, A B Sproul, and M A Green, in 1st World Conference on Photovoltaic Energy Conversion, Waikoloa, Hawaii, USA, December 1994 IEEE, to be published.

Innovative structures for thin film crystalline silicon solar cells to give high efficiencies from low quality silicon, A B Sproul, S Edmiston, S R Wenham, G Heiser and M A Green, in 1st World Conference on Photovoltaic Energy Conversion, Waikoloa, Hawaii, USA, December 1994. IEEE, to be published.