Interdigitated back contact solar cells with SiO2 and SiN back surface passivation

The results presented in this paper concern the study of interdigitated back contact solar cells (IBC SC) emitter passivation by means of comparison of full and point contact solar cells and two type of passivation layers (SiN and SiO2) as well as different values of the emitter sheet resistance. The fabrication of contacts in the form of points does not influence significantly the I–V characteristic parameters in comparison to full contact cells for highly doped emitters, however, improvement of Rsh is observed for a few point contact solar cells. A similar effect has been observed on higher sheet resistance emitters as well as a strong degradation of the dark current after the last annealing of the cell. We have attributed this effect to the short-circuiting of a too thin emitter.