Versatile Implied Open-Circuit Voltage Imaging Method and its
Application in Monolithic Tandem Solar Cells
Abstract
As the efficiency of perovskite silicon tandem solar cells is
increasing, the upscaling for industrial production is coming into
focus. Spatially resolved, quantitative, fast, and reliable contactless
measurement techniques are demanded for quality assurance and to
pinpoint the cause of performance losses in perovskite silicon tandem
solar cells. In this publication we present a measurement method based
on spectrally integrated photoluminescence (PL) imaging to extract
subcell-selective implied open-circuit ( i V oc ) images from monolithic
perovskite silicon tandem solar cells. We validate the approach using
spectrally resolved absolute PL measurements based on an integrating
sphere for the perovskite top cell and PL-calibrated carrier lifetime
images for the silicon bottom cell. Additionally, V oc measurements of
solar cells with low contact losses are used to validate the new
measurement technique. We find a good agreement of the i V oc images
with the validating measurements with a maximum deviation of well below
1 % compared to the validation measurements.