Ligand engineering on CdTe quantum dots in perovskite solar cells for suppressed hysteresis

The J-V hysteresis is one notorious issue in perovskite solar cells. Interface engineering represents one possible solution to this problem. Herein, we incorporated CdTe quantum dots (QDs) between perovskite and hole transporting layer, trying to combine the merits of CdTe and perovskite materials to achieve high device performance. The influence of surface ligands of CdTe QDs on device performance were studied, and it is found that the cells with CdTe-QD-in-perovskite solids showed highest efficiency (averaged 19.3%) and alleviated hysteresis, compared with cells modified by CdTe with other ligands (oleic acid, PbI2, CH3NH3I). Further studied revealed that the reduced hysteresis is partially contributed from faster hole extraction at the interface.170