Reducing non-radiative and radiative recombination in InGaAs quantum well solar cells

InGaAs quantum well solar cells are demonstrated with record-high open circuit voltages. Higher open circuit voltages result from the use of a novel structure incorporating a wide band gap barrier layer within a heterojunction depletion region and a step-graded InGaAs well to suppress both non-radiative and radiative recombination. Analysis of the open circuit voltage as a function of well energy suggests these devices are operating in a regime that exceeds traditional radiative limits on the performance of photovoltaic devices.