Spectrum on demand light source (SOLS) for advanced photovoltaic characterization

We report a multi-purpose spectrum-on-demand light source (SOLS), conceived primarily but not exclusively for the multiple and advanced characterization of photovoltaic (PV) materials and devices. The apparatus is a spectral shaper illumination device, providing a tunable and spectrally shaped light beam produced by modulating the intensity and/or wavelength range of a primary light source. SOLS stands out from the state of the art because it produces almost any spectrum on demand and delivers two types of output: a spectrally shaped and spatially homogeneous beam over its cross section for areal illumination or a spatially and spectrally split beam into its wavelength components, a unique capability suited to characterize lateral-tandem (Rainbow) solar cells. The tuneability from broadband to narrowband illumination enables two characterization devices into one, namely, a solar simulator for the determination of the power conversion efficiency and an external quantum efficiency measuring system. We expect the SOLS setup to accelerate material screening, enabling the discovery and optimization of novel multi-component materials and devices, in particular for emergent PV technologies like organic, metal halide perovskites, or multi-junction geometries, as well as novel PV applications such as indoors, building integrated, or agrivoltaics, among others.The Spanish Ministerio de Ciencia e Innovación (MICINN) is gratefully acknowledged for its support through Grant No. CEX2019-000917-S (FUNFUTURE) in the framework of the Spanish Severo Ochoa Center of Excellence program and the AEI/FEDER(UE) under Grant Nos. PID2021-128924OB-I00 (ISOSCELLES) and PDC2022-134001-I00 (SOLS-PV proof of concept). The authors also acknowledge the Catalan agency AGAUR for Grant No. 2021-SGR-00444. M.C.-V. acknowledges an FPI fellowship (Grant No. PRE2019-089855) from MICINN cofinanced by the European Social Fund, and M.G.-R. acknowledges the scholarship Grant No. FPU16/02631 from the Spanish “Ministerio de Educación.” M.C.-V. and M.G.-R. also acknowledge the Ph.D. program in Materials Science from the Universitat Autònoma de Barcelona, in which both were enrolled.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe