Ultrahigh-performance indoor perovskite quantum dot photovoltaics via ligand-passivation engineering

The advancement of perovskite photovoltaic (PePV) systems for harnessing indoor light energy has been accelerated by the advent of the Internet of Things (IoT). However, the commercialization of these systems is impeded by moisture instability and restricted carrier lifetimes. Perovskite quantum dots (PQDs) offer viable solutions for increasing stability despite the potential effects of their organic ligands on efficiency. In this study, a ligand passivation strategy was employed in PQD photovoltaics (PQDPVs) to enhance the carrier lifetime. The inclusion of 2-phenyl-4-(1,2,2-triphenylvinyl) quinazoline (2PACz) in the PQD film effectively reduced surface defects and suppressed trap-assisted charge recombination, resulting in a prolonged carrier lifetime. The charge carrier lifetimes in passivated PQDPVs increased by 35 %. Additionally, the matching of the energy level of the PQD changed after 2PACz passivation engineering with that of the 2PACz showed an advantage for hole transport. PQDPVs fabricated using 2PACz-passivated PQDs showed an impressive output power density (Pout) of 123.3 µW/cm2 (power conversion efficiency of 41.1 %) under a fluorescent lamp (0.30 mW/cm2; 1000 lx) owing to improved open-circuit voltage and fill factor. Moreover, the device maintained more than 80 % of its initial efficiency for 500 h in an ambient atmosphere. These findings highlight the potential of PQDPVs to compete with conventional PePVs for application in self-powered optoelectronic devices under dim illumination.