Volume 31: Clean Energy Technologies towards Carbon Neutrality

Device simulations: Reducing non-radiative recombination losses for achieving >15% efficient lead sulfide quantum dot solar cells Dandan Wang, Chao Ding, Meibo Xing, Haifeng Wu, Ruixiang Wang, and Qing Shen

Abstract

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 cms^-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