Study of p-on-n GaInP/sub 2//GaAs tandem cells

This paper describes the study on monolithic p-on-n GaInP/sub 2//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/sup +/- p/sup -/-n/sup -/-n/sup +/ structure for GaInP/sub 2/ top cell, while p/sup +/-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 GaInP/sub 2//GaAs tandem cells are as follows: The open circuit voltage V/sub oc/ = 2.397 V, the short circuit current density J/sub sc/ = 14.51 mA/cm/sup 2/, the fill factor F.F. = 0.873 and the conversion efficiency EFF=22.44% (AMO, 2/spl times/2 cm/sup 2/, 25/sub i/).