Effect of quantum dot position and background doping on the performance of quantum dot enhanced GaAs solar cells

The effect of the position of InAs quantum dots (QD) within the intrinsic region of pin-GaAs solar cells is reported. Simulations suggest placing the QDs in regions of reduced recombination enables a recovery of open-circuit voltage (V_OC). Devices with the QDs placed in the center and near the doped regions of a pin-GaAs solar cell were experimentally investigated. While the V_OC of the emitter-shifted device was degraded, the center and base-shifted devices exhibited V_OC comparable to the baseline structure. This asymmetry is attributed to background doping which modifies the recombination profile and must be considered when optimizing QD placement.