TOPCon Silicon Solar Cells with Selectively Doped PECVD Layers Realized by Inkjet-Printing of Phosphorus Dopant Sources

In this article, we evaluate an industrially relevant alternative for the formation of selectively doped n-type tunnel oxide passivating contacts (n-TOPCon) by means of inkjet-printing with the goal to provide a low contact resistance as well as fulfilling the requirements for screen-printing metallization. It is shown that inkjet-printing of phosphorus dopant sources for thick TOPCon layers deposited by plasma-enhanced chemical vapor deposition provides excellent surface passivation with the implied open-circuit voltage iVoc = 733 mV, implied fill factor iFF = 87%, and a high dopant concentration of Npoly-Si ⼠2 à 1020 as required to achieve low contact resistivities when using screen-printed pastes as contacting material. The Voc values of the prepared TOPCon solar cells of 697 mV confirm that the inks and inkjet processes are suitable for integration in TOPCon solar cells. Moreover, these cells enable promising conversion efficiencies of up to ηbest = 22.0% and o ffer a valuable set-up for further investigations on the correlations between inkjet processing and solar cell performance.