How Thin Practical Silicon Heterojunction Solar Cells Could Be? Experimental Study under 1 Sun and under Indoor Illumination

Solar RRL, vol. 6

Abstract

The transition toward thinner microcrystalline silicon wafers for their potential performance gain has been of interest in recent years. Theoretical predictions have estimated a maximum efficiency for silicon wafers to be at about 100−110 μm thickness. The potential and losses in silicon heterojunction solar cells prepared on wafers with thickness in the range of 60−170 μm with focus on open‐circuit voltage (V OC) and fill factor (FF) are studied experimentally. The applicability of thinner wafers for low light and indoor applications using light emitting diode (LED) lighting is also studied. The implied V OC (iV OC) is observed to increase with a decrease in wafer thickness according to theoretical predictions with absolute values approaching the theoretical limit. Unlike the iV OC, the implied FF is observed to decrease with wafer thickness reduction opposite to the theoretical predictions which are related to the effect of surface recombination. A combination of gains and losses results in a broad range of high efficiency under 1 sun for wafer thicknesses ranging from 75 to 170 μm with maximum of 22.3% obtained at 75 μm. As for indoor performance, thinner wafers show slightly better efficiency at lower light intensity under sun and LED illumination, promising improved performance for even thinner devices.

Authors 12

1. Ugochi K. Chime corresponding Aachen Faculty of Electrical Engineering and Information Technology

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Faculty of Electrical Engineering and Information Technology RWTH Aachen University 52074 Aachen Germany

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

   Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, 52074 Aachen, Germany

2. Leon Wolf

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

3. Viktoriia Buga

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

4. Daniel J. Weigand

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

5. Alaaeldin Gad

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

6. Julian Köhler

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

7. Andreas Lambertz

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

8. Weiyuan Duan

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

9. Kaining Ding

   Forschungszentrum Jülich

   Affiliation as printed

   IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

10. Tsvetelina Merdzhanova

    Forschungszentrum Jülich

    Affiliation as printed

    IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

11. Uwe Rau Aachen Faculty of Electrical Engineering and Information Technology

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    Faculty of Electrical Engineering and Information Technology RWTH Aachen University 52074 Aachen Germany

    IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany

    Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, 52074 Aachen, Germany

12. Oleksandr Astakhov corresponding

    Forschungszentrum Jülich

    Affiliation as printed

    IEK5-Photovoltaik Forschungszentrum Jülich GmbH 52425 Jülich, Germany