Concentrator solar cells
Concentrator solar cells are the core of concentrator photovoltaic systems. We have been working on this field since 1987 and we have achieved as main results: a) a single junction GaAs solar cell with an efficiency of 26.2% at 1000 suns in 1999; b) a dual junction GaInP/GaAs with an efficiency of 32.6% at 1026 suns in 2008 which was world record and c) a triple junction GaInP/GaInAs/Ge cell with an efficiency of 40% at 400 suns in 2014. In the development of concentrator solar cells (see figure 1) we follow the “LED-like approach” (that we proposed in 2000) which looks to the small sizes and optoelectronic techniques used in LEDs (Light Emitting Diodes) The efficiency increase from the 40% level requires the use of more than three subcells. This is why we are developing solar cells with four, five and six junctions. Metamorphic, lattice-matched dilute nitride and wafer bonding architectures are being investigated. Our goal is to reach 50% efficient solar cells. We work on the whole value chain of the concentrator solar cell, namely, modeling & simulation, MOVPE growth, material and device characterization, reliability and cost analysis. |
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Selected publications
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