Effective passivation of p+ and n+ emitters using SiO2/Al2O3/SiNx stacks: Surface passivation mechanisms and application to industrial p-PERT bifacial Si solar cells

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2018-11-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
9
356-364
Series
SOLAR ENERGY MATERIALS AND SOLAR CELLS, Volume 186
Abstract
In this paper, we present an effective emitter passivation scheme using SiO2/Al2O3/SiNx stacks. Our study shows that SiO2/Al2O3/SiNx stacks can well passivate both p+ and n+ emitters due to an excellent chemical passivation combined with a weak field-effect passivation. Good quality boron and phosphorus emitters were achieved over a broad emitter-doping range, as demonstrated by post-fired emitter saturation current of 20 and 30 fA cm−2, respectively. Based on the results obtained with SiO2/Al2O3/SiNx emitter passivation, we present an industrial roadmap for a p-PERT bifacial cell structure. Using this roadmap, we demonstrate industrial p-PERT bifacial cells with front side efficiency of 20.5%, rear side efficiency of 19.8% (bifaciality factor BF = 0.98) for rear textured cells and 17.5% (BF = 0.85) for rear planar cells. In particular, the cells with bifacial SiO2/Al2O3/SiNx passivation on both p+ and n+ emitters also demonstrate promising performance and a simplified cell process. The results show that SiO2/Al2O3/SiNx emitter passivation scheme is a promising candidate for photovoltaic industry.
Description
Keywords
AlO, Boron emitter, PERT, Phosphorus emitter, SiO, Surface passivation
Other note
Citation
Huang , H , Modanese , C , Sun , S , von Gastrow , G , Wang , J , Pasanen , T P , Li , S , Wang , L , Bao , Y , Zhu , Z , Sneck , S & Savin , H 2018 , ' Effective passivation of p + and n + emitters using SiO 2 /Al 2 O 3 /SiN x stacks: Surface passivation mechanisms and application to industrial p-PERT bifacial Si solar cells ' , Solar Energy Materials and Solar Cells , vol. 186 , pp. 356-364 . https://doi.org/10.1016/j.solmat.2018.07.007