Transparent Conductive Oxide Sputtering Damage on Contact Passivation in Silicon Heterojunction Solar Cells with Hydrogenated Nanocrystalline Silicon

Solar RRL, vol. 6

Abstract

Mitigating the adverse effect of transparent conductive oxide (TCO) sputtering on the passivation quality of the heterojunction contact is very critical for achieving high‐efficiency silicon heterojunction (SHJ) solar cells. Herein, n‐type ultra‐thin (5 nm) nanocrystalline silicon (nc‐Si:H) is utilized as a contact layer in rear‐junction SHJ solar cells. It is revealed that the TCO sputtering damage on the contact layer is caused by the ion bombardment during the sputtering process and cannot be fully recovered by low‐temperature annealing. A more severe passivation deterioration is observed for the devices with nc‐Si:H(n) having a higher microstructure factor. This result is explained by an increased ion penetration depth in the porous nc‐Si:H film. By applying denser nc‐Si:H(n) in SHJ solar cells, the front silicon film stack shows more resilience to sputter damage, yielding a remarkable cell performance on the M2‐size wafer with certificated power conversion efficiency (η) of 23.87%. The sputter damage on nc‐Si:H by TCO in SHJ solar cells is explored in depth for the first time from the perspective of silicon thin films.

Authors 7

1. Depeng Qiu Aachen Faculty of Electrical Engineering and Information Technology

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

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

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

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

2. Weiyuan Duan corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

3. Andreas Lambertz

   Forschungszentrum Jülich

   Affiliation as printed

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

4. Alexander Eberst Aachen Faculty of Electrical Engineering and Information Technology

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

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

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

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

5. Karsten Bittkau

   Forschungszentrum Jülich

   Affiliation as printed

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

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

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

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

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany

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

7. Kaining Ding

   Forschungszentrum Jülich

   Affiliation as printed

   IEK-5 Photovoltaics Forschungszentrum Jülich GmbH 52425 Jülich Germany