29.5%-efficient GaInP/GaAs tandem solar cells

Abstract

We report on multijunction GaInP/GaAs photovoltaic cells with efficiencies of 29.5% at 1-sun concentration and air mass (AM) 1.5 global and 25.7% 1-sun, AM0. These values represent the highest efficiencies achieved by any solar cell under these illumination conditions. Three key areas in this technology are identified and discussed; the grid design, front surface passivation of the top cell, and bottom surface passivation of both cells. Aspects of cell design related to its operation under concentration are also discussed.