Effect of external bias on multi-stacked InAs/AlGaAs quantum dots solar cell

We have investigated the effect of external bias on a 20-layer stacked InAs/AlGaAs quantum dots solar cell (QDSC) The external quantum efficiency (EQE) of QDSC increases between 760 and 1000 nm wavelength due to additive contributions from QD layers inserted into the p-n AlGaAs structure. On the other hand, the EQE response in the short-wavelength region with no external bias degraded by introducing the QD layer. Under irradiation of bias light with the wavelength of 970 nm, EQE recovers with increasing bias light power density. We believe that the bias light suppresses carrier recombination by photo-filling of states related to QDs, and improves the carrier collection.