Title:	The Impact of High Spectral Match: Using an LED Solar Simulator for Tandems
Author(s):	B. Mihaylov, B.C. Duck, C.J. Fell, T.W. Jones, K.F. Anderson, G.J. Wilson
Keywords:	Spectral Response, Tandem, LED, Solar Cell Efficiencies
Topic:	Perovskites and Other Non-Silicon Materials and Devices, Multijunctions/Tandems
Subtopic:	Tandems
Event:	38th European Photovoltaic Solar Energy Conference and Exhibition
Session:	3BV.2.60
Pages:	496 - 500
ISBN:	3-936338-78-7
Paper DOI:	10.4229/EUPVSEC20212021-3BV.2.60
Price:	0,00 EUR
Document(s):	paper, poster

Abstract/Summary:

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Spectral responsivity (SR) measurements on stable multi-junction (tandem) solar cells are never trivial, however the procedure is well-established and methods exist to correct for measurement artefacts. Perovskite/Silicon (PSK/Si) devices present a challenge however, since they typically exhibit metastability and degradation, even during the measurement. This complicates SR measurements, leading to uncertainty in the setup of the solar simulator for the primary current-voltage (I–V) measurement. We demonstrate a way to optimize the spectrum of a LED-based solar simulator so that both the spectral mismatch (SMM) and its sensitivity to the spectrum are small. The method leverages the inherent flexibility in the multichannel light source and combines it with known spectral responsivity data from a range of similar devices. The impact is that tandem solar cells can be measured accurately even with no prior information about their spectral responsivity. We estimate for a PSK/Si device the additional uncertainty in measured efficiency can be as low as 0.32%. This significantly reduces the exposure of the devices to light and voltage bias, thus minimizing metastability and degradation prior to the most important part of the measurement