Radiative band-to-band photoluminescence (PL) signal is detected in silicon solar cells and modules at approximately 1.1 eV. Recording this signal with hyperspectral push-broom camera has so far been conducted in controlled laboratory conditions. However, detecting band-to-band PL signal evoked by sun's excitation outside of laboratory setting poses a particular kind of challenge due to reflection detected by the imaging apparatus. To the authors' knowledge, there have only been a few successful attempts to remove the noise and uncover the PL signal detected in the field. They are based on collecting images of a module in different operating conditions. Present work applies this method in order to detect both the spatial and spectral distribution of the band-to-band PL signal in silicon solar modules with a push-broom scanner. Spectral distribution of the PL signal detected in one of the module's cells shows a signal in range 1.0-1.3 eV, where band-to-band PL signal from Si solar cells is expected to be seen. In addition, there seem to be solar cells with zero and negative PL signal. Further studies are needed.
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