The photoreflectance spectra for heavily dopedp‐type GaAs/SI‐GaAs structures have been measured at room temperature for the energies in the vicinity of the GaAsband gap. The complex photoreflectance function is defined and determined by means of a Kramers–Krönig analysis from the measured photoreflectance spectra. The modulus of the complex photoreflectance function gives us the critical point energy whereas the phase of this function can be used for a topographical study of the homogeneity of the internal electric field in the structure.

Basic knowledge about the factors and mechanisms affecting the performance of solar cells and their identification is essential when thinking of future improvements to the device. Within this paper, we investigated the current transport mechanism in GaAsN p-i-n solar cells grown with atmospheric pressure metal organic vapour phase epitaxy (AP-MOVPE). We examined the electro-optical and structural properties of a GaAsN solar cell epitaxial structure and correlated the results with temperature-dependent current-voltage measurements and deep level transient spectroscopy findings. The analysis of J-V-T measurements carried out in a wide temperature range allows for the determination of the dominant current transport mechanism in a GaAsN-based solar cell device and assign it a nitrogen interstitial defect, the presence of which was confirmed by DLTFS investigation.