Optimized duplicated-junction solar cells: An innovative approach for energy harvesting at ultra-high concentrations

The present study demonstrates the potential of duplicated-junction solar cell approach to overcome the limit imposed by the resistive losses in concentration photovoltaic systems. The proposed design consists of subdividing each subcell of the solar cell architecture into multiple, optically thin, p-n sub-junctions, therefore increasing the open-circuit voltage as well as reducing the delivered current and associated resistive losses. The concept is validated experimentally by the measured current-voltage characteristic of a 3xGaAs solar cell at one sun. Moreover, the experimental data allowed calibrating our theoretical model, based on the finite element method, developed for analyzing impact of proposed strategy at high concentrations. Simulation results, using Silvaco Atlas software, show that 3xGaAs cell can produce a maximum efficiency up to 33% at 3500 suns, under AM1.5D solar spectrum at 300 K.