Hydrogen ion passivated solar cells

Can hydrogen passivation improve the efficiency of silicon solar cells?

With the implementation of such processes for industrial silicon solar cells, efficiency improvements of 1.1% absolute can be obtained. Hydrogen passivation is widely used for silicon solar cells to reduce the recombination activity associated with a variety of performance limiting defects.

Can hydrogen passivate crystalline silicon solar cells?

Hydrogen passivation, such as forming gas annealing and alneal (aluminum anneal) process, has been investigated for high efficient crystalline silicon solar cell structures, because the hydrogen atoms can reduce the surface recombination velocity. However, hydrogen could not diffuse deeply to passivate various defects within the silicon bulk.

What are the benefits of hydrogen passivation in P-type solar cells?

P-type monocrystalline silicon solar cells receive benefits of hydrogen passivation of metastable defects such as the carrier-induced boron-oxygen (B-O) defect. [36, 37] B-O defects can form under the normal operating conditions in the field, causing a reduction in cell performance of up to 2% absolute.

Why do solar cells use hydrogen?

This is largely due to the complex behaviour of hydrogen in silicon and its ability to exist in many different forms in the lattice. For commercial solar cells, hydrogen is introduced into the device through the deposition of hydrogen-containing dielectric layers and the subsequent metallisation firing process.

Does hydrogen play a role in defect passivation?

Significant discrepancies in reported diffusivity data, and the challenge of measuring hydrogen in silicon, have led to many contradictions related to the involvement of hydrogen for defect passivation. A key defect in silicon solar cells plagued with contradictions is the B-O complex.

How does hydrogen passivation occur?

Presumably, hydrogen passivation occurs from the direct bonding of hydrogen to the defect such as the formation of dopant-hydrogen pairs, the passivation of dangling bonds, or defect-hydrogen complexes. In the process, the recombination activity of a given defect can be neutralised.