This report details how to develop innovative measurement techniques for laser doped samples that can allow high quality data to be collected relatively quickly and accurately.
Laser processing can be used in various ways as part of the solar cell manufacturing sequence. There exists an opportunity to improve existing manufacturing lines through the incorporation of laser processing, which can simplify the manufacturing process and allow an increase in solar cell conversion efficiency. However, industrial implementation requires that the laser processes are very well understood and optimised. This has proved difficult to do in the past, as it is quite time consuming to obtain reliable information on the properties of laser processed regions.
The aim of this project was to develop new techniques that would allow the fast and accurate determination of the properties of laser processed regions. In this way, the laser processes can be quickly optimised, and the conversion efficiency of solar cells that could be achieved from the new process can be accurately predicted.
We achieved the project goals by developing two measurement techniques as well as a new computer model that together allow a comprehensive determination of the properties of laser processed regions. We have demonstrated the advantages of these techniques over the state of the art prior to the commencement of this project. These techniques allowed new insights and a better understanding of what happens during laser processing. The improved understanding will guide the development of further laser processes.
To demonstrate the usefulness of the techniques developed, they were used to optimise two quite new and relatively unexplored laser processes. We were able to demonstrate that both approaches allow high solar cell efficiencies to be realised. Solar cells fabricated with one of these approaches achieved efficiencies of nearly 21%, significantly higher than most commercially made solar cells.