Increasing the efficiency of silicon heterojunction solar cells and modules by light soaking

Handle URI:
http://hdl.handle.net/10754/625637
Title:
Increasing the efficiency of silicon heterojunction solar cells and modules by light soaking
Authors:
Kobayashi, Eiji; De Wolf, Stefaan ( 0000-0003-1619-9061 ) ; Levrat, Jacques; Descoeudres, Antoine; Despeisse, Matthieu; Haug, Franz-Josef; Ballif, Christophe
Abstract:
Silicon heterojunction solar cells use crystalline silicon (c-Si) wafers as optical absorbers and employ bilayers of doped/intrinsic hydrogenated amorphous silicon (a-Si:H) to form passivating contacts. Recently, we demonstrated that such solar cells increase their operating voltages and thus their conversion efficiencies during light exposure. We found that this performance increase is due to improved passivation of the a-Si:H/c-Si interface and is induced by injected charge carriers (either by light soaking or forward-voltage biasing of the device). Here, we discuss this counterintuitive behavior and establish that: (i) the performance increase is observed in solar cells as well as modules; (ii) this phenomenon requires the presence of doped a-Si:H films, but is independent from whether light is incident from the a-Si:H(p) or the a-Si:H(n) side; (iii) UV and blue photons do not play a role in this effect; (iv) the performance increase can be observed under illumination intensities as low as 20Wm (0.02-sun) and appears to be almost identical in strength when under 1-sun (1000Wm); (v) the underlying physical mechanism likely differs from annealing-induced surface passivation.
KAUST Department:
KAUST Solar Center (KSC)
Citation:
Kobayashi E, De Wolf S, Levrat J, Descoeudres A, Despeisse M, et al. (2017) Increasing the efficiency of silicon heterojunction solar cells and modules by light soaking. Solar Energy Materials and Solar Cells 173: 43–49. Available: http://dx.doi.org/10.1016/j.solmat.2017.06.023.
Publisher:
Elsevier BV
Journal:
Solar Energy Materials and Solar Cells
Issue Date:
24-Jun-2017
DOI:
10.1016/j.solmat.2017.06.023
Type:
Article
ISSN:
0927-0248
Sponsors:
The authors are grateful to Yoshimi Watabe and Fumiharu Ishimura for the sample preparation of single cell modules. The authors are also grateful to Mathieu Boccard, Gabriel Christmann, Sylvain Nicolay, Philipp Löper, Jan Haschke, Raphaël Monnard, Jean Cattin, Andrea Tomasi, Gizem Nogay, Andrea Ingenito, Philipp Wyss, Josua Stuckelberger, Silvia Martin de Nicolas, Jonathan Champliaud, and Christophe Allebé for fruitful discussions. The simulations were done with the software package ASA of Delft University of Technology. Financial support from the Swiss Federal Office of Energy, EU FP7 program (CHETAAH Project, Contract No. 609788), and King Abdullah University of Science and Technology (KAUST) is acknowledged.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0927024817303318
Appears in Collections:
Articles; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorKobayashi, Eijien
dc.contributor.authorDe Wolf, Stefaanen
dc.contributor.authorLevrat, Jacquesen
dc.contributor.authorDescoeudres, Antoineen
dc.contributor.authorDespeisse, Matthieuen
dc.contributor.authorHaug, Franz-Josefen
dc.contributor.authorBallif, Christopheen
dc.date.accessioned2017-10-03T12:49:31Z-
dc.date.available2017-10-03T12:49:31Z-
dc.date.issued2017-06-24en
dc.identifier.citationKobayashi E, De Wolf S, Levrat J, Descoeudres A, Despeisse M, et al. (2017) Increasing the efficiency of silicon heterojunction solar cells and modules by light soaking. Solar Energy Materials and Solar Cells 173: 43–49. Available: http://dx.doi.org/10.1016/j.solmat.2017.06.023.en
dc.identifier.issn0927-0248en
dc.identifier.doi10.1016/j.solmat.2017.06.023en
dc.identifier.urihttp://hdl.handle.net/10754/625637-
dc.description.abstractSilicon heterojunction solar cells use crystalline silicon (c-Si) wafers as optical absorbers and employ bilayers of doped/intrinsic hydrogenated amorphous silicon (a-Si:H) to form passivating contacts. Recently, we demonstrated that such solar cells increase their operating voltages and thus their conversion efficiencies during light exposure. We found that this performance increase is due to improved passivation of the a-Si:H/c-Si interface and is induced by injected charge carriers (either by light soaking or forward-voltage biasing of the device). Here, we discuss this counterintuitive behavior and establish that: (i) the performance increase is observed in solar cells as well as modules; (ii) this phenomenon requires the presence of doped a-Si:H films, but is independent from whether light is incident from the a-Si:H(p) or the a-Si:H(n) side; (iii) UV and blue photons do not play a role in this effect; (iv) the performance increase can be observed under illumination intensities as low as 20Wm (0.02-sun) and appears to be almost identical in strength when under 1-sun (1000Wm); (v) the underlying physical mechanism likely differs from annealing-induced surface passivation.en
dc.description.sponsorshipThe authors are grateful to Yoshimi Watabe and Fumiharu Ishimura for the sample preparation of single cell modules. The authors are also grateful to Mathieu Boccard, Gabriel Christmann, Sylvain Nicolay, Philipp Löper, Jan Haschke, Raphaël Monnard, Jean Cattin, Andrea Tomasi, Gizem Nogay, Andrea Ingenito, Philipp Wyss, Josua Stuckelberger, Silvia Martin de Nicolas, Jonathan Champliaud, and Christophe Allebé for fruitful discussions. The simulations were done with the software package ASA of Delft University of Technology. Financial support from the Swiss Federal Office of Energy, EU FP7 program (CHETAAH Project, Contract No. 609788), and King Abdullah University of Science and Technology (KAUST) is acknowledged.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0927024817303318en
dc.subjectFill factoren
dc.subjectLight soakingen
dc.subjectPassivating contacten
dc.subjectSilicon heterojunctionen
dc.subjectSolar cellen
dc.subjectSolar moduleen
dc.titleIncreasing the efficiency of silicon heterojunction solar cells and modules by light soakingen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.identifier.journalSolar Energy Materials and Solar Cellsen
dc.contributor.institutionDepartment of Materials Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japanen
dc.contributor.institutionChoshu Industry Co., Ltd., 3740, Shin-yamanoi, Sanyo Onoda, Yamaguchi 757-8511, Japanen
dc.contributor.institutionÉcole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Rue de la Maladière 71b, CH-2002 Neuchâtel, Switzerlanden
dc.contributor.institutionCSEM PV-Center, Jaquet-Droz 1, CH-2002 Neuchâtel, Switzerlanden
kaust.authorDe Wolf, Stefaanen
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