Spectral dependence of photovoltaic cell conversion efficiency for monochromatic radiation

Photovoltaic cell conversion efficiencies for quasi-monochromatic radiation have been measured as a function of the wavelength. It has been proven that the conversion efficiency is nearly proportional to the wavelength of the input radiation as the theory predicts. Also, it has been shown that the efficiency increases as a logarithmic function of the input irradiance. In conclusion, highest conversion efficiency is realized by illuminating a photovoltaic cell by intense radiation of low energy photons close to the bandgap energy while satisfying sufficient absorption.