USE OF PHOTOACOUSTIC MEASUREMENTS IN THE ANALYSIS OF SOLAR CELLS.

Photoacoustic measurements provide calorimetric means for characterizing a photovoltaic cell. The authors apply the photoacoustic technique to the study of energy loss mechanisms in a solar cell. Results from a computer simulation of the photoacoustic signal of a photovoltaic device are in qualitative agreement with the experimental data. When a solar cell containing a back surface field is irradiated with weak, monochromatic light of long wavelength, its photocurrent increases with increasing forward bias. This anomaly originates from trap states at the back surface. Photoacoustic data appear to support this hypothesis.