4 Junction dilute nitride solar cell optimization: Comparing current matching approaches in detailed balance algorithms

The optimization of quadruple junction solar cell designs in the detailed balance limit via an equivalent circuit model for each sub-cell is explored using spectral sharing from three perspectives: (i) current matching at short circuit current (as per etaOpt software), (ii) corrected current matching at short circuit current and (iii) unconstrained short-circuit currents. At 1-sun illumination (968 W/m²), we report an efficiency increase of 1.3% absolute for the second current matching approach over the first, solely due to an increase in fill factor. For concentrated illumination at 1000 suns, the efficiency increase becomes 1.6% absolute.