Radiation effects on InAlGaAs / InGaAs quantum well solar cells

The response of InGaAs quantum well solar cells (QWSCs) to proton irradiation is presented. The QWSCs consisted of sixteen layers of 5 nm InGaAs QWs / 10 nm InAlGaAs barriers were embedded into the i-region of a 1.0 eV InAlGaAs solar cell, and the results were compared to a 1.0 eV InAlGaAs control solar cell. We report the results of 3 MeV proton irradiation using light J-V measurements of both of these devices. Due to the specific design of the structures in this study, QW devices were found to be less radiation tolerant than the control InAlGaAs devices. EQE measurements reveal that the diffusion length in the base layer of the junction has a significant affect on the loss in short circuit current of these devices. The quantum well structures showed a particular radiation robustness in comparison, largely due to the maintenance of the electric field at these fluences.