Light-induced performance increase of silicon heterojunction solar cells

Kobayashi, Eiji; De Wolf, Stefaan; Levrat, Jacques; Christmann, Gabriel; Descoeudres, Antoine; Nicolay, Sylvain; Despeisse, Matthieu; Watabe, Yoshimi; Ballif, Christophe

Light-induced performance increase of silicon heterojunction solar cells

Files

1.4964835.pdf (1.14 MB)

Type

Article

Authors

Kobayashi, Eiji
De Wolf, Stefaan

Levrat, Jacques
Christmann, Gabriel
Descoeudres, Antoine
Nicolay, Sylvain
Despeisse, Matthieu
Watabe, Yoshimi
Ballif, Christophe

KAUST Department

KAUST Solar Center (KSC)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division

Online Publication Date

2016-10-11

Print Publication Date

2016-10-10

Date

2016-10-11

Abstract

Silicon heterojunction solar cells consist of crystalline silicon (c-Si) wafers coated with doped/intrinsic hydrogenated amorphous silicon (a-Si:H) bilayers for passivating-contact formation. Here, we unambiguously demonstrate that carrier injection either due to light soaking or (dark) forward-voltage bias increases the open circuit voltage and fill factor of finished cells, leading to a conversion efficiency gain of up to 0.3% absolute. This phenomenon contrasts markedly with the light-induced degradation known for thin-film a-Si:H solar cells. We associate our performance gain with an increase in surface passivation, which we find is specific to doped a-Si:H/c-Si structures. Our experiments suggest that this improvement originates from a reduced density of recombination-active interface states. To understand the time dependence of the observed phenomena, a kinetic model is presented.

Citation

Kobayashi E, De Wolf S, Levrat J, Christmann G, Descoeudres A, et al. (2016) Light-induced performance increase of silicon heterojunction solar cells. Applied Physics Letters 109: 153503. Available: http://dx.doi.org/10.1063/1.4964835.

Acknowledgements

The authors gratefully acknowledge Jan Haschke, Silvia Martin de Nicolas, Raphaël Monnard, Jean Cattin, Andrea Tomasi, Gizem Nogay, Andrea Ingenito, Philipp Löper, Franz-Josef Haug, Philipp Wyss, Josua Stuckelberger, Jonathan Champliaud, and Christophe Allebé for fruitful discussions. Financial support of Swiss Federal Office of Energy, EU FP7 program (CHETAAH Project, Contract No. 609788), and King Abdullah University of Science and Technology (KAUST) is acknowledged.