Commercial carbon nanotube as rear contacts for industrial p-type silicon solar cells with an efficiency exceeding 23%

Commercially available single wall carbon nanotube (SWCNT) soots are combined with an organic passivation scheme and shown to be an efficient rear contact and alternative to ALD-Al2O3/PECVD-SiNx/laser treatment in conventional passivated emitter and rear cell (PERC) solar cells. Both low carbonaceous purity 60-70% and 95% SWCNTs are tested and a power conversion efficiency of over 23% is demonstrated. The approach is simple, scalable and completely eliminates the metal-semiconductor contact known to cause high interfacial recombi-nation in PERC technology. A low reverse saturation current density (J0) is achieved by varying the concen-tration and species of SWCNTs used and a full-area back surface field on an industrial sized (275.54 cm2) solar cell is obtained.

Automated summary

This study demonstrates that commercially available SWCNT soots, combined with organic passivation technology, can serve as an efficient rear contact and alternative to ALD-Al2O3/PECVD-SiNx/laser treatment in conventional PERC solar cells, achieving a power conversion efficiency of over 23%. This approach is simple, scalable, and eliminates the issue of high interfacial recombination caused by metal-semiconductor contact in PERC technology.