In the present study, a reference solar cell with ITO/ZnO/MAPbI3/Spiro-OMeTAD/Ag structure with one absorber layer (MAPbI3 perovskite) was simulated and simulation results were compared with real experimental results. Then, to improve the performance of the reference cell, a layer of lead sulfide quantum dot (PbS QD) was used as the second absorber layer to produce a double-absorber solar cell. It was found that by inserting the PbS QD layer between MAPbI3 and Spiro-OMeTAD, the efficiency of reference perovskite-based solar cells increases from 12.65 to 18.46% regarding the enhancement in current density (JSC) of the short circuit from 19.95 mA/cm2 to 30.45 mA/cm2. Using a QD absorber beside the perovskite layer could be an effective approach to increase light absorption and photo-carrier generation in the device. For this double-absorber device, the power conversion efficiency, filling factor (FF), and open-circuit voltage ( VOC) of 18.46%, 67%, and 0.91 V were obtained under 1.5 AM illumination, and all properties were discussed.
