The performance of photovoltaic (PV) solar cells is influenced by solar irradiance as well as temperature. Particularly, the average photon energy of the solar spectrum is different for low and high light intensity, which influences the photocurrent generation by the PV. In photovoltaic power ratings, a single solar spectrum, AM1. 5, is the de facto standard for record laboratory efficiencies, commercial module specifications, and performance ratios of solar power plants. In spite of similar technical parameters the amount of yearly produced energy may differ by notable percents. It results from the operation of solar trackers and also from the different spectral behavior of the different PV. This technical note provides an overview of the photovoltaic (PV) devices of today, and the spectral characterisation techniques used in the evaluation of their efficacy in the goal of harnessing a maximum of energy from the sun and artificial sources of light.
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