EFFICIENCY ENHANCEMENT FOR SCREEN PRINTED SOLAR CELLS ON QUASI-MONO WAFERS THROUGH HYDROGEN PASSIVATION OF DISLOCATIONS

摘要

The performance of solar cells fabricated on quasi-mono material, particularly from the central and upper regions of a seeded-cast ingot, tends to be dominated by recombination due to dislocations. This paper demonstrates the impact of these regions on both the effective lifetime of test structures as well as on the performance of standard screen printed solar cells. Furthermore it is shown that through appropriate processing it is possible to greatly reduce this impact. Specifically, incorporating advanced hydrogen passivation techniques results in a substantial enhancement in the effective minority carrier lifetime, which is shown to directly translate to significant improvements in final cell efficiency. Following hydrogenation, there appears minimal difference in quality between the wafers with and without these dislocations.