Processing of ultrathin silicon heterojunction solar cells bonded to a glass carrier

A method of processing ultrathin silicon solar cells by bonding them to a glass carrier is described. The method allows processing large area solar cells on the wafers with down to 10 micron thickness. In the method the rear side of a solar cell is processed on a stand-alone wafer. The cell is then bonded to a glass carrier followed by chemical thinning and processing of the front side. Finally, the cell is de-bonded from the glass carrier. This work applied bonding process previously developed at Arizona State University Flexible Electronics and Display Center to a SHJ solar cell. It was found that bonding material can withstand wafer thinning and acidic cleans used in SHJ processing. We also show that bonding material doesn't contaminate PECVD or sputtering chambers and doesn't prevent achieving very good surface passivation.