Performance improvements through gradient layers in transparent passivating contact solar cells

Cell Reports Physical Science, vol. 6, pp. 102658

Abstract

Transparent passivating contact solar cells using hydrogenated n-type nanocrystalline silicon carbide (nc-SiC:H(n)) utilize a double-layer stack consisting of one passivation-optimized and one conduction-optimized nc-SiC:H(n) layer. This double-layer configuration limits the fill factor ( FF ) due to the passivating layer's low electrical conductivity. This study enhances this structure by introducing a gradient layer that transitions from passivating-like to conducting-like properties. While replacing the passivating layer alone does not improve performance, when combining it with an ultrathin passivating seed layer, the gradient layer effectively balances voltage and FF trade-offs. This results in higher device voltage and FF . Microstructural analysis shows hydrogen content near the crystalline Si interface similar to the double-layer approach but with increased electrical conductivity earlier in the layer stack. These improvements boost both FF and open-circuit voltage by 0.6% absolute and over 4 mV, respectively.

Authors 6

1. Alexander Eberst corresponding Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany

   Jülich Aachen Research Alliance (JARA-Energy) and Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Schinkelstrasse 2, 52062 Aachen, Germany

2. Binbin Xu Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany

   Jülich Aachen Research Alliance (JARA-Energy) and Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Schinkelstrasse 2, 52062 Aachen, Germany

3. Karsten Bittkau

   Forschungszentrum Jülich

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany

4. Andreas Lambertz

   Forschungszentrum Jülich

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany

5. Uwe Rau Aachen

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany

   Jülich Aachen Research Alliance (JARA-Energy) and Faculty of Electrical Engineering and Information Technology, RWTH Aachen University, Schinkelstrasse 2, 52062 Aachen, Germany

6. Kaining Ding

   Forschungszentrum Jülich

   Affiliation as printed

   IMD-3: Photovoltaics, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany