Initial assessment of monocrystalline silicon solar cells as large-area sensors for precise flux calibration

As the precision frontier of large-area survey astrophysics advances toward the one millimagnitude level, flux calibration of astronomical instrumentation remains an ongoing challenge. We describe initial testing of silicon solar cells (SCs) as large-aperture precise calibration photodiodes. We present measurements of dark current, linearity, frequency response, spatial response uniformity, and noise characteristics of the Sunpower C60 SCs, an interdigitated back-contact 125 × 125 mm² monocrystalline SC. We find that these devices may hold promise as large-area flux calibration sensors and that further analyses over a broader range of operating conditions are necessary.