Co-diffused bi-facial PERT solar cells. (September 2017)

• Record Type: Journal Article
• Authors: Fellmeth, Tobias; Meier, Sebastian; Clement, Florian; Wolf, Andreas; Knauss, Holger; Havercamp, Helge
• Is Part Of: Energy procedia. Volume 124(2017)
• Page Start: 875
• Page End: 880
• Publication Date: 2017-09
• Subjects: Bi-facial -- PERT -- co-diffusion -- BSF -- Reverse bias; Power resources -- Congresses; Power resources -- Periodicals; Power resources; Conference proceedings; Periodicals; 333.7905
• DOI: 10.1016/j.egypro.2017.09.247
• Languages: English
• ISSNs: 1876-6102

Abstract

Abstract: The authors present a fully solderable, co-diffused and bi-facial PERT solar cell where the rear BSG/SiN stack acting both as dopant and passivation source reaching a mean efficiency of 20.4 %. The conductivity induced by the presence of the p + layer at the rear reduces series resistance losses significantly by simultaneously enabling the use of lowly doped Si wafers that reduce B-O degradation while maintaining a high fill factor. Parallel processed, mono-facial pendants reach the same efficiency level. A higher FF for the mono-facials is compensated by a higher Voc for the bi-facial PERT devices. SEM analysis on test structures show an overall superior, local Al-Si contact in terms of voiding and BSF thickness with reducing printed finger width. At reverse bias, the "conventional process" shows a typical behaviour for such architecture of elevated current flow around the edges. For the "adapted process" up to -12 V, the authors demonstrate a virtually shunt-free device exhibiting reverse currents far below 1 A with no additional process step.