Al2O3/Ag/Al2O3 passivating and conducting stacks for crystalline silicon solar cells

Abstract

The purpose of this work is to investigate the passivating and conducting layers of crystalline silicon solar cells. The Al2O3/Ag/Al2O3 stack was chosen because of the free carrier injection effect of this structure. A resistivity as low as 2.81×10−5Ωcm was achieved with a 16nm Ag interlayer. The current-voltage measurements indicate that the current density increases with the increasing thickness of the Ag layers. The passivation properties of the stacks were examined by effective minority carrier lifetime measurements. The annealing process was applied to study the thermal stability of the thin film stacks. The best sample yielded an effective surface recombination velocity of approximately 50cm/s and a resistivity of approximately 3.0×10−5Ωcm. Moreover, the fixed charges of the investigated structures varied according to the thickness of the Ag layers. The experimental results demonstrated the promising potential of Al2O3/Ag/Al2O3 stacks as passivating and conducting layers for crystalline silicon solar cells.