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

Abstract

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.

Combinatorial screening of wide band-gap organic solar cell materials with open-circuit voltage between 1.1 and 1.4 V

“…Besides V oc , the FF is another key aspect governing the indoor efficiency. We have performed a leakage current and shunt resistance analysis, using a custom built setup, 61 and the results are summarized in Section S11 and Fig. S9 of the ESI †.…”

RAINBOW Organic Solar Cells: Implementing Spectral Splitting in Lateral Multi‐Junction Architectures

“…Its functionality details are described elsewhere. [40,48] EQE Characterization: External quantum efficiency measurements were performed on a custom-made semi-automated experimental setup, with an associated LabVIEW controlling software. This experimental setup was coupled to a supercontinuum laser light source and a computercontrolled monochromator (LLTF contrast, Fianium) for filtering the white laser to provide a continuous spectral range.…”

“…To carry out such measurements, we have developed a setup capable of generating custom light spectra that are homogeneous and can be dynamically modified with a high degree of accuracy (Figure 3a). [40,48] This is achieved in three steps: First, incoming light is spatially separated into all its wavelength components with a dispersive element. Second, the spatially separated beam passes through a specifically designed dynamic mask, which blocks specific wavelength components, in this case, two motorized guillotines.…”

“…The full description of the setup will be published elsewhere, and details can be found in references. [40,48] To validate the model we have chosen to perform SOLS RAIN-BOW measurements on the wide-narrow-gap cell combination, because of its high calculated IoBC, and its optimal dividing wavelength range that falls well within the SOLS spectral shaping capabilities. The individual SOLS characterization of the red and blue cell provides us with insights to assess the validity of the model assumptions.…”