MODULATION SPECTROSCOPY CHARACTERIZATION OF INP AND GAAS SOLAR-CELLS

We used modulation spectroscopy to characterize InP and GaAs photovolt aic solar cells. The clear-cut Franz-Keldysh oscillations displayed by solar cell modulation spectra make it possible to directly measure th e electric field at the p-n junction of typical devices. By performing this measurement under different bias conditions, the impurity concen tration in the base of the solar cells was obtained. Measurements were made both using electrical modulation and electrical bias and, altern atively, using contactless optical modulation and optical bias. (C) 19 97 Elsevier Science Ltd.