PRINTED METALLISATION OF PHOSPHORUS DOPED SILICON SURFACES FOR SOLAR CELL APPLICATIONS

Abstract

This thesis focuses on the development and characterization of printed metallisation methods for high-efficiency silicon wafer solar cells. Metallisation of phosphorus doped surfaces using screen-printed silver (Ag) pastes is a well-established process. However, its performance is limited by several fundamental factors. Its inability to reliably print fine metal lines on the front surface of the solar cell results in significant shading losses. This work compares two high-throughput printing technologies, namely printing by screens versus stencils. Uniform print line definition and optimised Ag paste utilisation makes stencil printing the preferred choice for fine-line metallisation. Furthermore, the metal-silicon interface in a solar cell is a highly recombination active region that impacts the device voltage. A new method is developed to determine the metal contact recombination parameters. The electrical and microstructural properties of Ag contacts on phosphorus doped surfaces with different surface doping concentrations and junction depths are also investigated.