Consideration of High Bandgap Subcells for Advanced Multijunction Solar Cells

Multijunction solar cell theoretical modeling has been performed as a function of the subcell bandgap energies. This modeling guides the development of advanced multijunction cells. In this report we focus on analyzing the sensitivity of 3, 4, 5, and 6 junction solar cells to the bandgap energy of the high bandgap subcell(s) in the device. This work is motivated by the importance of high bandgap subcells for achieving high efficiency multijunctions, and the lack of proven high bandgap photovoltaic materials above 1.97eV. Modeling of 3-6 subcell multijunctions shows the importance of achieving high performance high bandgap subcells for high efficiency, particularly as the number of junctions increases. In this paper several practical situations are analyzed, including the use of the AM0 spectrum for space applications and low AOD (aerosol optical depth) direct spectrum for terrestrial concentrator applications