FABRICATION AND CHARACTERISATION OF CRYSTALLINE SILICON WAFER SOLAR CELLS FOR TANDEM APPLICATIONS

LI XINHANG

Publication

FABRICATION AND CHARACTERISATION OF CRYSTALLINE SILICON WAFER SOLAR CELLS FOR TANDEM APPLICATIONS

LI XINHANG

Abstract

Today, crystalline silicon wafer solar cells are approaching their practical efficiency limit of about 28%. Higher efficiency can be achieved by a tandem cell approach that incorporates a high-bandgap top cell on top of a silicon bottom cell. In this configuration, the design considerations for the silicon cell are different from those of a stand-alone single-junction silicon cells operating under the AM1.5G 1-sun standard spectrum. Therefore, in this thesis two types of silicon cells are developed for applications as tandem bottom cells. One is a passivated-emitter-rear-contact silicon cell with planar front surface, achieving a stand-alone 1-sun efficiency of 16.8% and a 2-terminal perovskite-on-silicon tandem efficiency of 17.8%. The other cell type is a laser-fired-contact silicon cell that allows low-temperature rear-side metallization, which could be applied to both 2-terminal and 4-terminal tandem integrations. The stand-alone efficiency is 19.2% under 1-sun AM1.5G and 29.1% under a truncated infrared spectrum with 269.5W/m2. Detailed device fabrication and characterization results for both types of silicon solar cells are presented.