Impact of the contacting scheme on I-V measurements of metallization-free silicon heterojunction solar cells

verfasst von

Malte Brinkmann, Felix Haase, Karsten Bothe, Karsten Bittkau, Andreas Lambertz, Weiyuan Duan, Kaining Ding, Hans Peter Sperlich, Andreas Waltinger, Henning Schulte-Huxel

Abstract

I-V measurements are sensitive to the number and positioning of current and voltage sensing contacts. For busbarless solar cells, measurement setups have been developed using current collection wires and separate voltage sense contacts. Placing the latter at a defined position enables a grid resistance neglecting measurement and thus I-V characteristics independent from the contacting system. This technique has been developed for solar cells having a finger grid and good conductivity in the direction of the fingers. The optimal position of the sense contact in case of finger-free silicon heterojunction solar cells has not yet been studied. Here, the lateral charge carrier transport occurs in a transparent conductive oxide layer resulting in a higher lateral resistance. We perform finite difference method simulations of HJT solar cells without front metallization to investigate the impact of high lateral resistances on the I-V measurement of solar cells. We show the high sensitivity on the number of used wires for contacting as well as the position of the sense contact for the voltage measurement. Using the simulations, we are able to explain the high difference of up to 7.5% in fill factor measurements of metal free solar cells with varying TCO sheet resistances between two measurement systems using different contacting setups. We propose a method to compensate for the contacting system to achieve a grid-resistance neglecting measurement with both systems allowing a reduction of the FF difference to below 1.5%.

Organisationseinheit(en)

Institut für Festkörperphysik

Externe Organisation(en)

Institut für Solarenergieforschung GmbH (ISFH)
Forschungszentrum Jülich
Meyer Burger Technology AG

Typ

Artikel

Journal

EPJ Photovoltaics

Band

14

Publikationsdatum

26.04.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Physik der kondensierten Materie, Elektrotechnik und Elektronik

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1051/epjpv/2023009 (Zugang: Offen)