Photoreflectance characterization of InP and GaAs solar cells

Work has shown that electroreflectance is a powerful nondestructive tool for studying the interface electric field distribution in semiconductor structures. The authors have studied the electroreflectance spectra of complete InP and GaAs solar cells with the main purpose of determining internal electric fields present in the structure of the cells. In the modulation spectra of the finished solar cells measured it was found that well enough defined Franz-Keldysh oscillations are present such that the electric field intensity can be accurately extracted from their periodicity. In addition the authors found that photoreflectance, a contactless variation of electroreflectance, can be used to find the bandgap energy of the solar cells´ material and to detect the presence of the electric field at the junction