EU PVSEC Programme Online
EU PVSEC 2021, 6 - 10 September 2021
Presentation: 2CV.1.3 Temperature-Dependent Suns-Voc and Suns-iVoc for Advanced c-Si-Based Solar Cell Characterization
Type: Visual
Date: Wednesday, 9th September 2020
08:30 - 10:00
Author(s): J.P. Seif, T.G. Allen, R. Basnet, A.H.T. Le, M.F. Zhang, Z. Hameiri
Presenter / Speaker: A.H.T. Le, UNSW Australia, Sydney, Australia
Event: Conference Conference
Session: 2CV.1 Characterisation & Simulation of Si Cells / Fabrication and Production of c-Si Silicon Solar Cells and Related Processes
Type(s) of Access:  Conference Registration
Topic: 2. 5 Characterisation & Simulation of Si Cells
Summary / Abstract: Characterization of high-efficiency solar cells by Suns-Voc is a well-known and wide-spread technique [1]. In comparison with light current-voltage (I-V) measurements, Suns-Voc provides more accurate information on diode parameters. It plays a key role in investigations of electric losses and loss mechanisms in photovoltaic devices. Photoluminescence (PL)-based techniques for cell and module characterization, on the other hand, are gaining importance both for academic research and for industry. Recently, a PL-based method able to extract the recombination parameters of fully metallized samples from effective lifetime data was presented [2]. In this work we combine Suns-Voc and the afore mentioned PL-based method. While Suns-Voc measures the voltage at the metallic terminals, the PL-based method indirectly measures the implied open-circuit voltage iVoc (Suns-iVoc) which is linked to the splitting of the quasi Fermi levels of electrons and holes inside the wafer. It depends mainly on recombination within the wafer, as well as at its surfaces. Comparing both methods allows for the identification of voltage losses [3]—from iVoc to Voc—associated with the metallic contacts. This direct comparison on a finalized device is not possible with the photoconductance decay method—from which iVoc is normally obtained—as it is capable to measure unmetallized samples only. We use this combined tool to characterize a selection of different photovoltaic cell structures aiming to pinpoint the commonalities and differences among them and support their optimization. Furthermore, with the aid of numerical simulations we seek to explain the differences observable in each subgroup of devices.