Study of p-on-n GaInP2/GaAs tandem cells

This paper describes the study on monolithic p-on-n GaInP₂/GaAs; tandem cells. The cell samples were produced by metalorganic vapor phase epitaxy (MOVPE) at lower gas pressure. A modified configuration of tandem cells is introduced, using p⁺- p^--n^--n⁺ structure for GaInP₂ top cell, while p⁺-n structure for GaAs bottom cell. This has brought out much improved photovoltaic performances of the top cells. The reason for doing this was revealed by a numerical modeling, which accounts for a field-aided collection. The resultant best photovoltaic parameters of GaInP₂/GaAs tandem cells are as follows: The open circuit voltage V_oc = 2.397 V, the short circuit current density J_sc = 14.51 mA/cm², the fill factor F.F. = 0.873 and the conversion efficiency EFF=22.44% (AMO, 2×2 cm², 25_i).