Mechanically stacked two-tandem concentrator solar cell concept

Modeling results and some data from experiments currently under study for a new photovoltaic (PV) structure representing the tractable device adaptation of a quadrispectral concept proposed some years ago are presented. Based on a four-band solar spectrum division, it combines a couple of two-bandgap monolithic tandem cells grown, respectively, on GaAs and InP in a mechanical stacking configuration. In the PV concentrator approach, the objective of this rainbow cell design is to demonstrate the feasibility of efficiencies on the order of 40% (100*AM0, BOL) and 45% (500*AM1.5), utilizing III-V semiconductor materials currently used in optical fiber communication systems. In studying the influence of airmass values, the InP substrate-based booster tandem of universal use, either in space or in terrestrial applications, is found. Considering the GaAs-based tandem structure, an Am1-to-AM3 analysis leads to specification of the optimal top bandgap value. Projections of expected experimental efficiencies of this stacked two-tandem concentrator cell show that the objectives are realistic.<
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