Efficiency limits for space multi-junction concentrator solar cells

Efficiency limits of single-junction and multi-junction concentrator solar cells are established from the thermodynamic principle of detailed balance. The maximum efficiency limit of single-junction solar cells is 35% at 500 suns, while that of 2-junction solar cells which meet the current matching condition is 46%. At the same condition, the maximum efficiency limit of 3-junction solar cells with GaAs as middle subcell is 52%.