Application of AlGaInP with Sb Incorporation in Lattice-Matched 5-Junction Tandem Solar Cells

It is well known that conventional GaInP/GaInAs/Ge three-junction (3J) solar cells are difficult to continue to ascend when the efficiencies reach 32% and 42% under AM0 and AM1.5D concentrated, respectively. In AlGaInP/AlGaInAs/GaInAs/GaInNAs/Ge five-junction (5J) solar cells, the performance of the AlGaInP, AlGaInAs and GaInNAs sub cell is the key factor for conversion efficiency of the 5J solar cell. We investigate the AlGaInP/AlGaInAs/Ge 3J solar cell. By incorporating surfactant trimthylantimony into the AlGaInP material, the crystal quality of AlGaInP is improved and the spectrum absorption range of AlGaInAs is extended. The current density of each sub cell exceeds 11.3 mA/cm^2 as is desired. Then we apply this 3J structure to grow the lattice-matched 5J solar cell and obtain the short circuit current of 134.96 mA, open circuit voltage of 4399.6 mV, fill factor of 81.7% and conversion efficiency of 29.87%.