Investigations of diffusion barriers for application in back-contacted solar cells

The characterization of barriers against phosphorus diffusion for application in back-contacted solar cells by using the sheet resistance imaging (SRI) method is investigated. The focus is set on a screen-printable TiOxlayer, which is compared to a thermally grown and photolithographically patterned SiO2-layer. Within the measurement error the effectiveness of the TiOx-layer as a diffusion barrier is proven. The high resolution of the SRI allows to observe structures in the diffused areas of very small scale.