Device simulations: Toward the design of >13% efficient PbS colloidal quantum dot solar cell

•Performance assessment of MgZnO (MZO) and TiO2 ETL based PbS CQD has been done.•Optimized MgZnO and TiO2 ETL based devices reflected 13.59% and 13.94% conversion efficiencies.•The influence of PbS-TBAI/ETL interface defect density (IDD) has also been studied.•While increasing the IDD, reduction in carrier collection observed particularly at lower wavelengths, i.e., 13% power conversion efficiency (PCE). In the initial steps, calibration has been done to achieve the state of the art PCE of 9.4%, followed by device optimization. The optimisation is carried out in term of doping density of HTL and ETL, and a device is finalised with doping density of 5 × 1017 cm−3 for both, ETL and HTL. MZO and TiO2 ETL based devices with said doping reflected 13.59% and 13.94% conversion efficiencies. The influence of PbS-TBAI/ETL interface defect density (IDD) has also been studied where IDD is varied from 1 × 1013 cm−2 to 1 × 1018 cm−2 while keeping the rest of the device parameters intact. The results show a noteworthy reduction in the PV performance of the device at higher IDD. External quantum efficiency (EQE) is also obtained to understand the carrier collection. The result shows that carrier collection reduces particularly at lower wavelengths, i.e., 600 nm. To understand the carrier dynamics for the correlation of the data, energy band diagram (EBD) is obtained for all the performed variation. All the study reported is performed using SCAPS-1D simulator.