ANALYSIS OF LATERAL INJECTION EFFECTS IN OPERATIONAL SOLAR CELLS

摘要

Operational features of solar cells, particularly the lateral injection effects due to voltage build-up in the emitter region between the cell fingers, are becoming increasingly important with the improvements of modern cell technologies. To account for the lateral injection effects, a refined model is built by incorporating pseudo-photogeneration sources into the widely used transmission line model which consists of distributed elemental solar cells connected by resistive elements. A quantitative analysis demonstrates the key dependencies on cell and material parameters. It is shown that such effects reduce the emitter resistance and bulk recombination losses compared to the standard analysis and are more evident for high performance solar cells with a range of common features such as high voltage and current density output, lightly-doped base and emitter, narrow finger spacing, large bulk diffusion length and good rear surface passivation. The impact of lateral carrier injection on luminescence measurements is also noted and discussed.