Temperature dependence on the energy gap selection in two cell, four terminal tandem solar cell design

Temperature effects on the choice of the optimum energy gap combination (OEGC) for a two-cell, four-terminal tandem system are considered. The OEGC variation with temperature and the variation of the constant system efficiency contour curves with temperature are presented by using the typical GaAs_1-xP_x and Si experimental values. Calculation shows that OEGC shifts to higher energy values with increasing temperature under the optimum AM1.5 tabulated spectra photon flux approximation formula. Temperature dependence of a single-cell energy gap for fixed bottom cell and the material property effects are also considered. As an example, the design for GaAs_1-xP_x and Si tandem system is presented