Light-induced performance increase of silicon heterojunction solar cells
De Wolf, Stefaan
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
KAUST Solar Center (KSC)
King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal, 23955-6900, Saudi Arabia
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AbstractSilicon 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.
CitationKobayashi 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.
SponsorsThe 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.
JournalApplied Physics Letters