Triple junction InGaP/InGaAs/Ge solar cells for high concentration photovoltaics application: Degradation tests of solar receivers

Today, the III–V compound semiconductor solar cells represent the most promising photovoltaic technology to achieve the grid parity, thanks to their proven capability to work at high concentration factors (H-CPV: high concentration photovoltaics) with demonstrated conversion efficiencies higher than 40% in the spectral conditions typical of the Earth surface (AM1.5D). One of the issues to be investigated in the H-CPV systems is the reliability of the solar cell receivers. In fact in concentration conditions the thermal and mechanical stress on the solar cell, mounted on receivers, is very significant with respect to flat panel technology. This paper proposes a method, typically used in the LED industry, to test, in accelerated conditions, the H-CPV solar receivers. The receivers, based on III–V solar cells, size 2.1 × 2.1 mm 2 from CESI, were built by chip on board technology at CRP labs, and characterized for 800 h to simulate 20 years of in-field operation in concentration regime (500×).