This is the final report for the Advanced High Efficiency Silicon Solar Cell project.
Report extract
The objective of this project was to develop atomic-scale thin films that can be used as part of a passivating contact or surface passivation film. We developed innovative materials for both passivating electron and hole contacts enabled by doping of promising binary transition metal oxides. Aluminium doped titanium shows a significantly higher level of surface passivation for minority carriers as well as a considerably lower contact resistance for majority carriers. Zinc doping of nickel oxide can alleviate its poor contact performance on crystalline silicon and in combination with an amorphous silicon interface passivation layer, we demonstrated one of the most promising passating hole contacts to date. In both cases, we demonstrated that doping improves the thermal stability of the contact. We also showed that the contact resistance between screen printed silver and a phosphorous diffused emitter is significantly reduced by capping the silicon nitride antireflection coating with a thin aluminium oxide film. This process is not only demonstrated on the lab scale but is successfully transferred to high-volume manufacturing in collaboration with our industry partner Leadmicro.
