High efficiency solar cells based on AlInGaP

Aim of this work, is the study of the properties of Aluminium Gallium Indium Phosphide for the realization of the next generation high-efficiency multi-junction (MJ) solar cells. (Al_xGa_1-x)_0.50In_0.50P (AlInGaP) is a semiconductor with a high direct bandgap that can be tuned between 1.81 eV and 2.00 eV varying the Al content in the range 0<x¿0.12. This makes AlInGaP one of the most promising candidates for the manufacture of the top junction layers in multi-junction solar cells. In a five junction structure AlInGaP/InGaP/AlInGaAs/InGaAs/Ge, the use of AlInGaP with high Al content may lead to solar cells with maximum theoretical efficiencies above 40% in AM0 conditions. In this paper, we report the results of the material characterization we have carried out on AlInGaP single junction (SJ) solar cells grown by MOCVD, highlighting its electrical and optical behaviour as a function of the Aluminium content. The best performing cell we have obtained so far showed an open circuit voltage of 1.473 V, and a short circuit current of 15 mA/cm².