Optimization of Multi-Junction Solar Cells for the Orbit of Mars

Abstract

Photovoltaic (PV) devices have been used in space applications since 1958 and need to be constantly optimized in terms of specific power (W/kg). For the next decade, Mars is one important pursued destination by NASA and, as such, optimized PV designs will be needed. This work presents optimal designs in terms of bandgap energy configuration for multijunction solar cells operating at the Mars’ orbit conditions. For this, a physical model using blackbody radiation was implemented to calculate the solar spectrum at different orbital points and the PV solar cell temperature. By means of a computer simulation based on the Schockley-Queisser detailed balance model, power conversion efficiencies are mapped and the optimal bandgap energy combination is obtained for each configuration. As results, we obtained for the optimized double junction solar cell an efficiency of 45.3% with bandgaps of 0.90/1.60 eV and 51.7% for the best triple junction solar cell with bandgaps of 0.75/1.22/1.84 eV.