Fast and effective extraction for equivalent shunt resistances of triple-junction concentrator solar cells

Fast and effective extraction of equivalent shunt resistance for each subcell of GaInP/GaInAs/Ge triple-junction concentrator solar cells is presented. The two-diode model of single junction was introduced to establish the equivalent circuit of triple-junction solar cells. The current-voltage characteristic of the triple-junction solar cells was measured under AM1.5D spectrum, C = 576 and T = 303 K. Equivalent shunt resistance of each subcell was extracted from its estimated current-voltage curve. The estimated current-voltage curve of the triple-junction solar cells shows a good agreement with the experimental data in 0.31% deviation. The degradation in the equivalent shunt resistance for Ge subcell was intentionally introduced to indicate the mechanism of current-matching operation for different subcells, with the maximum output power of the triple-junction solar cells deteriorating from 3.5 to 3.17 W. The results can offer performance analysis and optimum design of photovoltaic applications.