Lead sulfide quantum dots solar cells (PbS QDSCs) have recently received substantial attention due to their
unparalleled photoelectric properties that can lead to a new record theoretical efficiency in thin film photovoltaic devices. However, the high voltage losses of PbS QDSCs induced by non-radiative recombination
losses bring about the low device performance. In this study, a real planar heterojunction PbS QD-based solar cell structure of FTO/PbS-EMII/PbS-EDT/Au is successfully simulated and then theoretically analyzed
the effects of these determining factors on device performance via drift-diffusion modeling. After modulating these factors, a new device is finalized with defect density (Nt) of 10^15 cm^-3
in absorber layer and acceptor density (NA) of 10^18 cm^-3 in hole transport material (HTM) as well as surface recombination velocity of 10 cms^-1 at absorber/HTM interface, which can deliver a power conversion efficiency (PCE) of 17.08%, with a 27.21% improvement in open-circuit voltage (VOC). This method used in this study can provide access guidelines and accelerate the efficiency improvements in PbS QDSCs.
Keywords voltage-loss, non-radiative recombination loss, power conversion efficiency