Computer simulation of the photocurrent collection coefficient in solar cells based on the textured thin-film Al xGa 1− xAs–GaAs heterostructure

Abstract

We calculated photoconversion efficiency in textured solar cells based on thin-film Al x Ga 1− x As–GaAs heterostructure using the ray optics approximation. Most calculations were performed for the case when regular microrelief was a set of V-like grooves with base angle of 45°. Taking into account antireflection properties of SiO 2 film deposited onto Al x Ga 1− x As film, as well as of Al x Ga 1− x As film itself, it was shown, in particular, that the reflection coefficient averaged over the solar radiation spectrum in the GaAs absorption region was below 1%. When calculating short-circuit current, we took into account both reflection coefficient decrease and growth of photon free path in p-GaAs layer. Aiming at provision of the highest photoconversion efficiency, we obtained the conditions for optimisation of grid area and doping levels in p- and n-GaAs layers.